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How Do I Change the Oxygen Sensor in a 1995 Chevrolet Astro Van

Prior to the second phase of onboard diagnostics (OBD II), implemented in 1996, many vehicles (including the 1995 Chevrolet Astro Van) came equipped with a single oxygen sensor. This sensor was placed on the manifold or front exhaust pipe to monitor the mixture emitting from the exhaust. Emissions that indicated the engine was running vehicles too lean (too much air) or too rich (too much fuel) would trigger the sensor to communicate to the computer and set off the malfunction indicator lamp. In 1996, the number of oxygen sensors doubled or even quadrupled on vehicles in order to also monitor efficiency of the catalytic converter.

Instructions

1

Apply the parking brake on the Astro Van and then pull the primary hood release latch on the drivers-side kick panel.

2

Open the hood by releasing the secondary hood release latch and then support the hood with the hood prop rod. This will allow some light through the engine compartment for more visibility when changing the oxygen sensor.

3

Lift the front end of the van with the jack and then support it on jack stands placed under the concave frame rails in the front.

4

Put on the safety glasses, gather the remaining items needed and then crawl under the front of the van.

5

Locate the catalytic converter at the center of the exhaust system and follow the exhaust system to the front of the engine. The oxygen sensor is located on the front pipe, below the passenger-side seating area.

6

Spray the penetrating lubricant onto the thread connection of the oxygen sensor-to-front pipe mating surface. Allow a few minutes to pass for the spray to penetrate.

7

Follow the wire on the end of the oxygen sensor to the plug connection of the wire harness (about 8 inches away). Use the small, slotted screwdriver to unlock the clip retainer on the wire harness connection and then unplug the oxygen sensor wire from the wire harness plug.

8

Place the oxygen sensor socket onto the ratchet and align the wire of the oxygen sensor through the slot of the socket. Place the socket firmly onto the oxygen sensor and apply counterclockwise pressure to loosen it from the front pipe. Remove the sensor.

9

Inspect the new direct-fit oxygen sensor threads. Many come equipped with a light coating of electrically conductive anti-seize compound. If there is none on the threads, spread a light coating of the anti-seize compound on the threaded section of the oxygen sensor only. Do not get the compound on the electrode of the sensor.

10

Hand-thread the new sensor into the exhaust port on the front pipe and tighten using fingers as much as possible.

11

Tighten the sensor fully with the socket and ratchet. Only snug the sensor to the front pipe. The threads of the sensors are much softer than the port and can easily strip if over-tightened.

12

Reconnect the oxygen sensor wire to the wire harness plug.

13

Start the engine up and then crawl back under to check for any obvious exhaust leak coming from the oxygen sensor port. If necessary, tighten the sensor a little more until there is no leak.

14

Lower the Astro Van and release the parking brake.

Posted by Unknown at 3:00 AM

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Labels: 1995, a, astro, change, chevrolet, do, how, i, in, oxygen, sensor, the, van