Directions on changing 02 sensor

[Zippy M3]

Mine went out at about 48,000 miles. The car feels a little faster now after I installed the new one. Dealers in the SoCal area qouted me $250-290 so I just save myself $150-190 bucks by doing myself.

Things you need:
1. BMW Jack and jack stands
2. Universal O2 sensor socket. ($9.99 from PEP boys or Kragen)
3. Open wrench to hold onto the head of O2 sensor tool
(1 1/8 inch). Make sure you buy a long one so that you will get more leverage.
4. O2 Sensor ($85 from European Performance or $90 from Alexander or VOB BMW)
5. Can of WD-40

Procedure:
1. Warm up the car for about 5-10 min. This will make it easier for you to unbolt the O2 sensor.
2. Lift the car up and slide under to locate the O2 sensor. It's on top of the Cats.
3. Apply some WD40 to the area where the O2 sensor meets the cats. I tried it 3 times without applying the WD40 and I couldn't get it off.
4. Disconnect the wiring harness and plug the O2 sensor removal tool on top of O2 sensor.
5. Use the wrench to turn the special tool which will simultaneously turn the O2 sensor counter clockwise. Don't burn yourself when touching the Cats! Use all your upper body muscle to twist. The O2 sensor is hard to remove because it has been there for a long time and has gone through thousands of heat cycles.
6. Replace the old sensor with new one and screw it on with just the O2 tool.
7. Install the wiring harness.
8. Drive around for a couple miles and the check engine light will turn off.

There you are done!

[JT-KGY]

What special O2 sensor tool? Is that the #2 on the list?

2. Universal O2 sensor socket. ($9.99 from PEP boys or Kragen)

Isn't there two O2 sensors??
Oh, yours is a 95 right?

thanks,

[Zippy M3]

Yup the 02 Sensor Tool and Socket are the same thing ($9.99) at PEP Boys. Also my car is a 95 M3 so the instructions might be different for 96+ M3's.

[JT-KGY]

Ya.. I believe that the 96+ has more than one sensor...
Some correctly me if i'm wrong.

Btw, coming down to hear the AA? Or you bought something already??

[jww///95]

One other note...


Make sure to liberally apply a coating of anti-sieze to the threads of the new o2 sensor before installing it!