Where is the oxygen sensor location on a 2000 VW Passat?

Answer 1

Late Model (Around 2000 or newer) VW Jettas and Passats have nearly identical exhaust systems. There are two oxygen sensors (aka 'O-2 Sensors), and both are located in the exhaust piping system.

Some places won't let you renew your license tags until I replace the sensors! The reason is pollution. O2 sensors are there to assure that there is plenty of oxygen mixed with the gasoline, so that efficient combustion can happen. If the combustion is oxygen-starved, your car ends up spewing unburnt gasoline fumes into the atmosphere - which is a lot worse than burnt gasoline fumes.

What You Will Need:

For starters, Oxygen sensors look quite a bit like a spark plug, and are changed in much the same way. For your Passat/Jetta, you will need the following tools:

* #10 Metric box-end, open-end, or socket-style wrenches

* #22 deep-well socket wrench (or maybe 23, heck a 7/8" worked for me)

* Groove-joint or slip-joint pliers (Channel-Lock 12" or 10" are great)

* 12" Crescent-style adjustable wrench

*If you are installing a "Universal" sensor, rather than an OEM sensor, it will have loose wires at the end, which you will need to splice yourself - so you'll want this stuff too:

* Wire cutters and strippers

* Volt-Ohm meter

* Electrical Tape

* Waterproof wire-splicers (the silicon-filled wirenuts are great)

A WORD ABOUT 'Universal' VS OEM sensors:

Universal sensors are indentical to OEM sensors (on the sensor end), and have loose wires on the connector-end. To use a universal part, you'll need to chop the connector off the old sensor, and splice it onto the new sensor, typically, its a piece of cake to match it all up.

Universal sensors are just as good as OEM, and they sell for about half of OEM price.

Getting Started:

Before buying parts, we've got to make sure we know exactly what we need. The 2002 Jetta had a 5-wire sensor on the front and a 4-wire on the back.

jack up your car - crawl under there and look at those sensors. The back one is basically right smack in the middle of the car on the bottom. Scoot back till your head is under the catalytic converter (bulgey thing in the exhaust pipe, probably has a metal grille around it). Right there behind it, you'll see your rear o2 sensor poking out of the pipe's side. Wires run from that sensor past the catalytic converter into a small black plastic box, where they meet the wires from the front sensor, or your car's "computer brain", also called the ECM.

While you're down there, grab that metric-10 wrench and take that plastic cover off. You'll see a reddish connector for the rear sensor and a black connector for the front. Take a moment and count how many wires come out of the two connectors.

In my case, it was front= 5-wire, rear = 4-wire. I used a universal, and it's wires were color-coded exactly the same as my original part. Had the colors been different, the universal sensor also had a matchup chart

I ordered mine online and payed only about $150 for both.

Change out the rear sensor first - unhook the rear sensor wire. Then take your crescent-wrench and twist that sensor out of the pipe. It will probably take some mild pressure, or even light tapping on the wrench to break it loose.

If your new rear sensor is Univ - go make your splices in a more comfortable spot. If you bought rear-OEM, just screw in the new sensor, plug it up, and stuff the wires back into their little clips.

Ok front sensor time - this one is a little harder, because there's a lot less room to work. It's located under the hood, on the back side of the motor, very close to the firewall. Your local auto parts retailer might be able to rent you a specialty tool for changing this sensor, but beware - in many cases the rental price is within a few bucks of buying the tool to keep for yourself and your car.

I ended up using a very stout handheld cutting plier to chop the old sensor in half, trying to make the cut as near to the bottom of the sensor as possible - ratcheting-out the remains of the old sensor, spinning in the new one, and routing those wires back to our friend the black plastic box. Once those wires we're tucked and Mr Black Box remounted.