Fix It

The 1998 Dodge pickup uses a crank sensor to feed detailed information to the power train control module to indicate the current position of the crankshaft as it rotates, as well as the crankshafts revolutions per minute (rpm). The crankshaft position sensors data determines when to fire the fuel injectors. On gasoline engines, it also determines when to fire the ignition coil to light the fuel-air mixture. Intermittent problems with the crankshaft position sensor cause hesitations and stalling of the vehicle. A continuous error with the crank sensor will prevent the vehicle from starting. Testing the crankshaft position sensor requires access to the sensor and plug.

Instructions

Gasoline Engines

1

Set the parking brake of the 1998 Dodge pickup truck. Pull the hood release handle. Open the hood.

2

Disconnect the negative battery cable. Loosen the 10 mm retaining nut on the battery cable clamp using a 10 mm wrench. Pry the battery cable off the negative battery post by twisting side to side by hand. The negative battery post has a "-" label next to it.

3

Stand on the passenger side of the truck. Place the work light next to the exhaust manifold as close as possible to the firewall.

4

Lean over the fender. Extend the telescoping inspection mirror in between the back of the cylinder head and the firewall.

5

Angle the mirror to inspect the edge of the transmission bell housing where it meets the engine block. A steel bracket secured by two 10 mm bolts with a three-wire harness retains the crankshaft position sensor, which reads gaps in a ring of the flywheel.

Diesel Engines

6

Open the hood of the 1998 Dodge pickup, and disconnect the negative battery cable using a 10 mm wrench.

7

Lie down face up on an automotive creeper, and slide under the drivers side of the vehicle just behind the tire, taking the wrench and the trouble light with you.

8

Hang an automotive trouble light underneath the vehicle.

9

Remove the three 10 mm bolts retaining the starter to the transmission bell housing using a 10 mm wrench. Remove the starter.

10

Look directly between the engine block and the location from which you removed the starter. The crankshaft position sensor is a black plastic sensor with an aluminum retaining bracket held in place by a single 10 mm bolt. The crank sensor has a three-wire harness plugged into it.

The crank position sensor in a General Motors Northstar engine is part of the sensing and diagnostic system that is controlled by the powertrain control module (PCM). The crank position sensor sends information to the PCM about the position of the crankshaft relative to the engine block. The PCM uses this information to determine when to actuate specific electronic components, such as the ignition. When the crank sensor fails, the engine will not start. Replacement sensors are available from Cadillac dealerships and local auto parts stores.

Instructions

1

Place the vehicles transmission in the park or "P" position. Shut down the engine and set the parking brake. Let the vehicle cool for at least 60 minutes before proceeding.

2

Open the hood and disconnect the negative battery lead using a battery terminal wrench.

3

Locate the crank position sensor on right side of the engine block, approximately three inches above the oil filter housing. It is made from black plastic and is connected to the engine with a 10 mm bolt.

4

Depress the locking tab on the sensors electrical connector and unplug the connector from the sensor. Remove the bolt holding the sensor to the engine, using a 3/8-inch ratchet and a 10 mm socket. Grip the sensor with a slip-joint pliers and gently remove it using a twisting/pulling motion.

5

Lubricate the new crank sensor with a small amount of clean engine oil. Install the new sensor into the engine block using a twisting/pushing motion. Reinstall the sensors retaining bolt and reattach its electrical connector.

6

Reconnect the negative battery lead. Start the engine and verify that it operates properly. The engine should start within three seconds of cranking and run smoothly.

The crankshaft position sensor -- also known as the CKP sensor --detects crankshaft position and rotation on the 2005 PT Cruiser. The sensor relays this information to the electronic control unit and helps determine ignition and fuel injection timing. Wear or damage to the crankshaft position sensor can lead to poor performance or even a non-running condition. The sensor is above the front motor mount so some disassembly is required to replace it.

Instructions

1

Set the parking brake and chock the rear wheels. Turn the ignition switch to the Off position.

2

Jack the front of the vehicle up. Support the vehicle using jack stands.

3

Locate the sensor on the front of the engine just below the starter. Locate the bending strut and structural collar just below the sensor.

4

Remove the five mounting bolts from the strut, using a ratchet and socket. Remove the strut from the engine. Remove the three remaining bolts from the collar, using a ratchet and socket. Move the power steering hose aside and then remove the collar from the engine.

5

Lift up on the locking tab on the sensor electrical connector. Unplug the electrical connector from the sensor.

6

Wipe the surrounding area using a clean rag to remove any dirt or debris that may find its way into the sensor hole.

7

Remove the sensor retaining bolt, using a ratchet and socket. Pull the sensor out of its hole.

8

Lubricate the O-ring on the new sensor with clean engine oil. Insert the new sensor in the hole and push it in with a slight twisting motion. Align the sensor mount with the bolt hole and install the retaining bolt. Tighten the bolt to 80 inch-pounds, using an inch-pound torque wrench and socket.

9

Install the electrical connector onto the sensor terminal. Ensure that the terminal lock snaps into position.

10

Hold the collar in its position between the transmission and the engine oil pan. Move the power steering hose into position below the collar. Install the collar-to-oil pan bolt through the forward hose support and collar bolt hole and then tighten it finger tight.

11

Place the bending strut in its position and start the upper strut-to-transaxle bolt. Do not tighten the bolt at this time.

12

Insert the lower strut-to-transaxle bolt through the strut and collar and start it. Do not tighten the bolt at this time.

13

Install the strut-to-block bolt on the passenger side corner of the strut and then tighten it finger tight.

14

Insert the collar-to-oil pan bolt through the rear power steering hose support and rear collar hole and then tighten it finger tight.

15

Tighten the three collar-to-transaxle bolts to 75 foot-pounds, using a foot-pound torque wrench and socket.

16

Install the remaining two strut-to-engine block bolts. Tighten the remaining five bolts to 45 foot-pounds, using a foot-pound torque wrench and socket.

17

Remove the jack stands and lower the vehicle using a jack.

Trying to work with an O2 sensor without the proper tools may result in a myriad of problems. An oxygen sensor plays an important role as it measures the amount of oxygen in both the gas or liquid that the sensor is analyzing. Should a problem arise with the O2 sensor and it needs to be repaired or replaced, the importance of having the appropriate O2 sensor tools on hand increases significantly.

Oxygen Sensor Wrench

Reaching an oxygen sensor is often a challenge as it is generally located in a hard-to-reach space. The oxygen sensor wrench was created for just this purpose, as it is capable of replacing and installing new oxygen sensors, or simply giving the oxygen sensor a "checkup." Oxygen sensors wrenches are generally 22 mm, and vary in style based on what tool is needed for a particular O2 sensor (such as rusty or overheated sensors).

Oxygen Sensor Tester

The oxygen sensor tester tool measures the response time of the O2 sensor. If the O2 sensor, when tested, is unable to move from under 175mV to over 800mV in under 100mS upon snapping the throttle, then the test is failed, indicating the need for a new O2 sensor.

Oxygen Sensor Socket

The oxygen sensor socket tool is specifically designed to assist in removing the O2 sensor from the exhaust manifold. Alternatively, a 22-mm socket may be used if you are unable to acquire an oxygen sensor socket. The socket is placed over the O2 sensor and turned clockwise to loosen it, with heat (via letting the car warm for five minutes) and oil applied if you are unable to loosen it.

The air temperature sensor on the 1997 Chevrolet Tahoe monitors the temperature of the air flowing through the intake into the filter. The engine computer regulates the fuel to air ratio based on the temperature readings from the sensor. Buy a new sensor from an auto parts retailer, and change it at home. The sensor mounts in an accessible location and requires no disassembly to access it.

Instructions

1

Raise the hood of the Tahoe. Support it with the prop rod.

2

Locate the air cleaner assembly at the top of the engine compartment, near the firewall. The air cleaner assembly is a large black box with air intake hoses attached to either side and clips securing the cover.

3

Look for a small wire running to the passenger side of the air cleaner assembly, just above the intake hose. The air temperature sensor connects to the end of the wire, threaded into the air cleaner assembly.

There are two oxygen sensors integrated into the exhaust system of the 2001 Saturn SL. The sensors help the 1.9-liter four-cylinder engine generate an ideal fuel-to-air ratio for optimum emissions. One sensor is located near the manifold and monitors this mixture. If the mixture becomes compromised (too much air makes the mix too lean; too much fuel makes the mix too rich), the sensor transmits a trouble code to the computer in the car. The rear sensor monitors the efficiency of the catalytic converter, which filters the harmful exhaust gases and converts them into less-harmful emissions.

Instructions

Upstream Sensor

1

Start the engine of the Saturn on a level ground for at least five minutes to warm the engine. This will help expand the metal of the manifold and sensor junction. Be caul and dont let it run too long, because it wont take long for the manifold and sensor to get hot enough to burn you.

2

Open the hood and locate the upstream sensor at the bottom of the manifold in the front of the engine. Disconnect the wire harness plug connection.

3

Spray penetrating lubricant along the threads of the sensor where it screws into the manifold and allow it to soak in for a few minutes.

4

Place the socket onto the ratchet and place the sensor wire into the slot of the socket (or feed the wire through the box end of a 22mm wrench) and turn the sensor counterclockwise to remove it from the manifold.

5

Inspect the new sensor before inserting it into the port hole in the manifold. Most quality aftermarket sensors have a light coat of high-temperature anti-seize compound on the threads of the sensor. If there is none on the threads, apply a very light coat to the threads only. Avoid getting any on the sensor itself.

6

Thread the sensor into the manifold porthole by hand, then tighten snugly. Do not over-tighten the sensor or youll strip the few threads it has and will ruin it. Plug the wire from the new sensor back into the wire-harness connector.

Downstream Sensor

7

Park the Saturn on a hard, level surface and then apply the parking brake (after warming the engine for five minutes; again, this will expand the metal of the exhaust pipe and sensor junction). Use the vehicle jack to lift the front of the Saturn, one front quarter panel at a time, high enough to place a jack stand under each front frame rail.

8

Put on safety glasses and crawl underneath the Saturn with the remaining items.

9

Locate the downstream sensor near the catalytic converter (in the center of the undercarriage under the front seats of the passenger cab).

10

Disconnect the wire-harness connection, then spray the threads with penetrating lubricant. Allow a few minutes to let the spray soak in. Use the ratchet and socket or 22mm wrench as described in Step 4 of Section 1 to remove the sensor from the exhaust piping.

11

Insert the new sensor (again making sure it has a light coat of high-temperature anti-seize compound on the thread section only) into the porthole of the exhaust pipe, and tighten snugly. Reconnect the wire of the sensor to the harness plug connection.

Before changing the camshaft sensor on your 1992 Buick Park Avenue, you must determine its location on the engine; the sensor is tucked away under the water pump, and while you can see it from the top of the engine, replacing it requires you to work under the front of the car. A replacement sensor is available from most auto parts stores or through a Buick dealership.

Instructions

1

Open the hood of your Park Avenue and locate the water pump on the front of the engine. You will see the water pump is the front-center of the engine block.

2

Look near the base of the water pump pulley, along the bottom edge: You will see an electrical connector and harness.

3

Follow the harness in toward the block, until you can see a small, round sensor threaded into the block--this is the camshaft sensor.

MAP is an acronym for manifold absolute pressure. A MAP sensor is an electronic control that works in conjunction with the intake manifold, a system of tubes and chambers that carry a mixture of air and fuel to the intake valves.

Function

A MAP sensor measures the pressure of the air channeled to the carburetor before it passes through the intake manifold. The signal that the MAP sensor emits changes in accordance to the pressure it detects.

Signals and Changes

The MAP sensors signals helps the engine control module determine what changes need to be made in the fuel mixture. these changes include how much fuel is injected and when cylinders are ignited.

Importance of Readings

Without accurate readings from the MAP sensor the proper air-fuel mixture is not maintained. This has a direct effect on the performance of the engine.

Faulty MAP Sensors

If the MAP sensor malfunctions, the "Check Engine" light should come on, although it may not stay lit. Engine performance will be drastically reduced. One common performance issue is hesitation when attempting to accelerate. This is a result of the loss of horsepower that is characteristic of a vehicle has a bad MAP sensor.

Bad MAP sensors also contribute to an increase of auto emissions.

2001 Chevrolet Silverados use a hub-mounted wheel sensor system that consists of an electro-magnetic sensor and a notched reluctor wheel on each front wheel. The reluctor wheel spins at the same RPM as the wheel and the electro-magnetic sensor records this information in pulses. The PCM and ABS computers decode this information and use it determine wheel speed. By determining the wheel speed, both computers can tell if a wheel is locked up or spinning faster than the other. In order to diagnose a faulty wheel sensor, you must monitor the data stream with a scan tool and also confirm that each sensor is receiving voltage.

Instructions

1

Lift the front portion of vehicle with a jack and support it with jack stands; both front tires must be at least 6-inches off of the ground. Place wheel chocks behind the rear wheels and apply the parking brake.

2

Switch the ignition to the ON position and connect a scan tool to the trucks data port under the dashboard below the steering wheel. Navigate to the live data menu and monitor the wheel speed sensors; they should both read zero.

3

Turn on the engine and lightly depress the throttle while monitoring the scan tool. The wheel speed sensor output readings should match the speedometer output. If one sensor does not then it is most likely faulty.

4

Turn off the engine but leave the ignition on and lie down on a mechanics creeper. Roll underneath the car and examine the wheel speed sensor wires for fraying or cuts.

5

Unplug the connector from the wheel speed sensor. Probe the light blue wire for the left-front wheel sensor and the tan wire for the right-front wheel sensor with a digital multimeter. The specified voltage value is 1.8 to 12 volts. If the multimeter reads less than 1.8 volts then find and repair the short in the wire and retest the sensor. If the voltage reading is within specification then replace the wheel speed sensor.

The oxygen sensor on your 1996 Jeep Cherokee helps regulate the fuel consumption and emissions. The sensor is threaded into the exhaust manifold and monitors the oxygen saturation in the trucks exhaust. The Cherokees computer adjusts the fuel-and-air mixture combusted in the engine based on the oxygen saturation. If your truck begins to burn a noticeably greater amount of fuel compared to its normal fuel consumption, buy a replacement oxygen sensor from an auto parts store and change it at home.

Instructions

1

Lift the front of the Cherokee with a jack until it sits high enough to fit jack stands underneath it for support. Place the jack stands under the frame rails just behind the front wheels. Lower the Cherokee so that it rests securely on the jack stands.

2

Disconnect the electrical connection from the oxygen sensor. Remove the sensor with a wrench or oxygen sensor socket attached to a ratchet.

3

Spread a thin layer of anti-seize compound on the threads of the new sensor. Do not get anti-seize compound on the sensor head. Thread it into place by hand. Tighten the sensor with a wrench or a socket and ratchet.

4

Connect the wiring harness connection by pressing it together until it clicks. Lift the truck with the jack until you can remove the jack stands. Return the truck to the ground.

Depending on the year of the Ford Taurus, there may be two or more oxygen sensors present in the exhaust system. In the common 3.0-liter 6-cylinder models, there are four sensors. Read and diagnose the trouble code that set off the "check engine" light to ensure youre replacing the correct sensor.

Instructions

1

Drive the Taurus onto a car lift. Put on safety glasses and crawl underneath the car.

2

Locate the sensor you need to replace. Two of them are screwed into each side of the Y-pipe coming off each manifold; there are two more downstream located after each catalytic converter.

3

Unplug the oxygen sensor from the wire harness.

4

Remove the oxygen sensor, using socket and ratchet. If necessary, heat up the pipe surrounding the oxygen sensor with a torch for easier extraction. Allow the pipe to cool down before continuing.

5

Apply a light coat of anti-seize lubricating compound to the threads of the new oxygen sensor. Be caul not to get any of the compound onto the head of the sensor.

6

Thread the sensor into the porthole of the exhaust pipe. Tighten with the ratchet and oxygen sensor socket.

7

Plug the oxygen sensor wire back into the wiring harness.

A Tracker is a small sport utility vehicle that was sold under the GEO and Chevrolet nameplates from 1989 to 2004. The Chevrolet Equinox took the Trackers place in the 2005 model year. The oxygen sensor on your Tracker makes sure the correct air/fuel ratio is achieved by sending signals to the engines electronic computer module. Your engine will not run at its maximum efficiency if the oxygen sensor is not operating properly. The first step in replacing the oxygen sensor in your Tracker is to remove the old one.

Instructions

1

Set the parking brake. If the engine has been run recently, let it cool for a few hours before you begin.

2

Raise the vehicle with a hydraulic jack and place jack stands under your Trackers frame to support its weight. Lower the hydraulic jack and set it aside.

3

Crawl under the vehicle on the right hand side (drivers side) near the drivers door. Locate the catalytic converter, which is mounted in-line with the exhaust pipe.

4

Locate the oxygen sensor which is mounted in the exhaust pipe near the rear of the catalytic converter.

5

Remove the wiring harness connector from the oxygen sensor by squeezing in the connector tabs with your fingers while simultaneously pulling the connector from the sensor.

6

Remove the sensor from the exhaust pipe by turning it out with an adjustable wrench in a counterclockwise direction.

Unlike the first mass-produced cars of a century ago, cars today have advanced control systems that are computer dependent. Being computer dependent, more and more information about how the car is functioning goes to the on-board computer. The vehicle speed sensors are the gatherers of this information.

Vehicle Speed Sensor Description

Cars manufactured today are dependent on on-board computers. The computer receives the information it needs to have a car operate properly from strategically located vehicle speed sensors. Most vehicle speed sensors are of the permanent magnet type. They function similarly to a cam shaft or crankshaft sensor. The installed sensors are either in the transmission case or rear differential assembly. When a speed sensor fails, the cars check engine light comes on and a code goes to the computer and can be read at a service station.

Locating Speed Sensors

This code indicates which sensor has failed and what the problem is. Occasionally, a sensor will fail without sending a code. If the driveability of the car is suspect, say the power steering isnt working and the ABS brakes are stuttering, a mechanic can check the vehicles manual and quickly find if the same speed sensor is controlling both modules.

Speed Sensors Control Many Functions

Modules or functions that use information from vehicle speed sensors include the variable assist power steering unit where the information from a speed sensor regulates the power steering pressure with higher pressure at low speeds and vice versa. This makes things like parallel parking maneuvers easier.

A cars anti-lock braking system (ABS) also uses information from a speed sensor to decide when a wheel has locked up and thus commands the ABS to cut pressure in order for the driver to maintain control of the car. While some cars use separate sensors for the ABS, it is common that the computer uses the information from the wheel sensors to act as a vehicle speed sensor. For example, many newer Ford vehicles use a rear axle mounted speed sensor for ABS and vehicle speed functions that are computer related.

Both traditional and hybrid cars use information from vehicle speed sensors for the speedometer display.

Many new cars have developed suspension systems that use vehicle speed sensor information to control the height of the ride. They adjust the ride down for better control at higher speeds for improved maneuverability.

Automatic transmissions must have the information from a vehicle speed sensor to decide shift strategy.

Additionally, cruise control depends on speed sensor information to know when to engage and when to disengage, as well as when to cruise at a set speed.

All Electronic Engine Control (EEC) systems use some speed sensor information to perform their tasks.

The knock sensor is responsible for monitoring the engine block for abnormal vibrations or internal components running out of balance. The sensor sends the information to the engine computer (ECU) and illuminates check engine light on the car, indicating the need for service. Replacement knock sensors are available from the dealer or most auto-parts stores. You need no special tools to replace your Nissan Pathfinders knock sensor.

Instructions

1

Locate the knock sensor on the back of the engine, just below the intake manifold. The sensor is a round, metal object with a single wire coming off its top.

2

Grasp the wire at the boot with your hand and pull it off the sensor. Set the wire off to one side and place a wrench on the hex portion of the sensor.

3

Rotate the sensor counterclockwise to remove it from the block. Discard the old sensor and thread a new one in its place.

4

Tighten the sensor until it is snug, using the wrench, then push the wire you removed from the old sensor onto the top of the new sensor. Do not use any thread-locking compound on the sensor, as it may affect its sensitivity and operation.

The oxygen sensor is an integral part of your Dakotas emissions system. It monitors the amount of oxygen in the exhaust. When an O2 sensor fails, your Dakota may hesitate or your fuel mileage may noticeably decrease. If your Check Engine light comes on, the O2 sensor may be to blame. Most auto parts stores will scan the computer for you to determine the problem at no cost. Purchase replacement sensors from an auto parts store or Dodge dealership.

Instructions

1

Lift your Dakota using a jack. Secure the truck on a set of jack stands so that you can comfortably work under it.

2

Locate the downstream oxygen sensor on the pipe behind the catalytic converter, running beside the frame rail. Disconnect the wiring from the sensor by pulling it straight out of the connector. Remove the O2 sensor using an oxygen sensor socket and a ratchet.

3

Install the replacement sensor with the oxygen sensor socket and the ratchet, turning it clockwise until it is secure. Torque the sensor to 22 foot-pounds with a torque wrench. Connect the wiring harness to the sensor by plugging it into the connection on the sensor.

4

Locate the upstream O2 sensors on either side of the transmission oil pan. There is an exhaust pipe running on each side of the pan with sensors in each one. Disconnect the wiring harness from each of the sensors then remove the sensors with the oxygen sensor socket and ratchet.

5

Install the new sensors in each location using the oxygen sensor ratchet. Torque the sensors to 22 foot-pounds with a torque wrench. Attach the wiring harness to the sensors by plugging them straight into the connections on the sensors.

6

Raise the vehicle up with the jack and remove the jack stands. Lower the vehicle to the ground.

The Chevy Blazer has the same 4.3 liter engine, the same chassis and the same exhaust components from 1994 to 1999. This includes the two oxygen sensors. The bank one sensor is located on the left side (drivers side) of the front exhaust Y-pipe. The bank two sensor is located just before the catalytic convertor in the exhaust pipe. Which oxygen sensor needs to be replaced will require an OBD II (On Board Diagnostics II) computer code reader or scan tool to determine the culprit. They are removed the same way, but the bank two sensor is much easier to get to. However, the parts and labor estimate may to replace the sensor may help you decide to take on the job yourself with just a few tools.

Instructions

1

Drive the 1999 Blazer up on car ramps to raise the front end. If you do not have car ramps, lift the front of the Blazer on a flat, level paved or concrete surface using a floor jack and two jack stands placed under the front frame rails. Apply the parking brake.

2

Place a wheel chock behind one of the rear wheels.

3

Put on the safety glasses and crawl under the Blazer (on a creeper if you have one) and bring the remaining tools with you.

4

Locate the oxygen sensor to replace. The bank one sensor is up under the left drivers side just forward of the front exhaust Y-pipe. The bank two sensor is located in the exhaust pipe just forward of the catalytic converter.

5

Follow the wire harness plugged into the oxygen sensor youre replacing. Using the small straight edged screwdriver, press in the lock clip of the plug and unplug the oxygen sensor wire from the harness.

6

Place the 22 millimeter wrench or oxygen sensor socket and ratchet onto the oxygen sensor and turn it to the left to release it. If it does not want to release, light the hand held portable propane torch and heat the exhaust pipe around the edge of the oxygen sensor. Do not heat the oxygen sensor, too. Just the pipe around it. Try to loosen the sensor until youre successful. If you had to use the torch, allow the exhaust pipe to cool down and just take a break.

7

Apply a light coat of high-temperature anti-seize lubricant to the threads of the new oxygen sensor only if there is not already some on them.

8

Screw the new oxygen sensor into the port. Tighten with the wrench or socket and ratchet. Do not over-tighten. The sensor only has about 4 to 5 threads and stripping those threads would be futile to the sensor.

9

Plug the sensor wire back into the wire harness.

10

Collect all the tools and debris from under the Blazer. Remove the wheel chock and lower the Blazer.

When one of the multiple oxygen sensors detect a lean mix of burned fuel to oxygen ratio or a bad circuit relay in your Ford Explorer Sport Trac, it will trip the "check engine" light. Finding the faulty sensor will require having the computer of the Explorer scanned. You can purchase quality aftermarket direct-fit oxygen sensors from parts stores now and many will be glad to scan the computer for free in order to sell your the parts you need.

Instructions

1

Raise the front end of the Explorer Sport Trac by driving it up onto car ramps. Apply the parking brake and place a wheel chock behind one of the rear tires.

2

Put on the safety glasses and gather the tools, replacement sensor and creeper if you have one. Crawl under the front of the Explorer Sport Trac.

3

Locate the sensor to be replaced. These sensors are screwed into the exhaust pipes and components and wired to wire harnesses that communicate to the computer system of the Sport Trac. The information of which sensor to replace should have already been obtained. Follow the exhaust piping from the engine manifold back until you have located the correct sensor.

4

Locate the sensor wire outlet plug. Some of the sensors on the Sport Tracs have a tricky plug to get at. Remove the plastic plug clip from the frame of the Sport Trac by prying it out with the screwdriver, but be careful not to damage the wire harness side of the outlet. Unplug the oxygen sensor wire from the wire harness.

5

Use the ratchet and socket to remove the sensor. Place the sensor wire into the slot on the side of the socket.

6

Screw in the new oxygen sensor and tighten. Be careful not to over-tighten or you could damage the threads to the new sensor.

7

Plug the oxygen sensor wire into the wire harness and fasten it back to the frame if you removed it. Gather the tools and creeper and crawl out from under the Sport Trac. Remove the wheel chock and back the Sport Trac off of the ramps.

The job of your Volvo S80s oxygen sensor is to regulate the fuel and air ratio in your car. It also controls your gas mileage. If the oxygen sensor malfunctions, your S80 will run poorly, and its gas mileage will decline. With a few tools, most people can replace the oxygen sensor safely.

Instructions

1

Locate the oxygen sensor on your pre-catalytic converter. It is near the right front wheel well of your S80.

2

Detach the two small air intake pipes by hand from the air box and from the blowoff valves. Twist off the large air intake pipe as well from the air box and the rear turbo. This provides access to the oxygen sensor. Spray WD-40 over the existing oxygen sensor to make it easier to remove.

3

Use the 7/8-inch wrench to remove the failed sensor. Locate the stock sensor wire near the engine lift loop near your engines firewall. Connect the ends of the stock sensor wire to the new oxygen sensors wires using the crimp connectors.

4

Rub a small amount of anti-seize paste onto the new oxygen sensor threads. Do not get any paste on the sensor itself, because that could cause it to fail. The paste will make removal easier the next time.

5

Screw in the new oxygen sensor, and tighten it enough with the wrench that it cannot be loosened easily. Reattach the air pipes to the valves.

The oxygen sensors in your 1998 Honda Accord help regulate the fuel consumption of your car. When an oxygen sensor fails, your car begins to burn too much fuel and you gas mileage declines dramatically. The 1998 Accord contains two oxygen sensors located in the exhaust pipe on either end of the catalytic converter. It is best to replace both together to avoid having another one fail immediately after the first replacement. Buy replacement sensors from an auto parts retailer or Honda dealer.

Instructions

1

Raise your 1998 Honda Accord with a jack and secure it on a set of jack stands. Position the car high enough to work comfortably beneath it.

2

Locate the oxygen sensor you want to change. Disconnect the electrical connection at the top of the sensor. Squeeze the retaining clip and pull the wiring connector straight off the sensor.

3

Remove the oxygen sensor from the exhaust pipe using an oxygen sensor socket and ratchet. Insert the new oxygen sensor by hand to prevent cross threading the new sensor. Torque the sensor to 33 ft.-lbs. with your torque wrench.

4

Reconnect the wiring harness on the new oxygen sensor. Press the electrical connection straight onto the new sensor until it clicks.

5

Repeat the process on the other sensor if needed. Raise the car with the jack and remove the jack stands. Lower the car to the ground.

Modern automobiles rely on sophisticated computerized engine management systems that include fuel injection, and monitor the air/fuel ratio by means of oxygen sensors in the exhaust system. Thus, oxygen sensors are an integral part of the engine system.

Air/Fuel Ratio

The air/fuel ratio for a gasoline engine has an optimal value of 14.7 to 1. This ratio results in good performance, and also reduces harmful emissions such as carbon monoxide and nitrogen oxides. Oxygen sensors monitor and maintain this critical ratio.

Performance and Emissions

Too much fuel in the air/fuel mix results in a "rich" mixture, and produces excessive unburned hydrocarbon emissions. Too little fuel results in a "lean" mixture, which produces excessive nitrogen oxide emissions. The fuel/air mix changes in response to data from the oxygen sensors, which monitor these emissions to make sure that the mix is neither too rich nor too lean.

Computer Management

A properly functioning engine management system uses fuel injection metering, a computer program and emissions sensors to ensure optimal engine performance, and the lowest possible level of harmful emissions, under a wide variety of operating conditions.