[RobertBarden]

How do I replace the O2 sensor in my 2004 GMC Envoy? It looks pretty simple but I have never done it and just wanted a little bit of instructions on doing it.

Thanks to anyone who helps.

Bob

 

[Super 88]

It would help to know if you have the I6 engine or the V8.

If it's the I6, it's very easy to do. The front o2 sensor is on the passenger side of the engine, very easy to get to and see. Simply unplug the wiring harness, get out your trusty o2 sensor socket and remove it. Mine was pretty easy to remove even around 50,000 miles.
Most new sensors come with a little anti-seize already on them. Just reinstalled the new one, plug it in and you are good to go. I disconnected the battery before starting this, just to be safe and to reset the computer. This is literally a 15 minute job.

 

[RobertBarden]

Thanks

Sorry didn't give the I6 description but that is what it is. This was very helpful and I want to thank you for the reply... Thanks Again

 

[rbarrios]

super88 is right.
ill add my 2 cents...

Seems that if you live in areas with road salt--- it may be a little harder when removing the sensor. some have had to use a torch to heat up the manifold to remove it..... so if you live in salt country--- then be careful removing it....

If youre like me-- and live in Southern California or places where theres no salt on the roads- then it should be easy.

I changed mine- I think it was around 130,000.
It came out so easily---- I actually had more trouble undoing the connector clip- than unscrewing the sensor.

I turned the wheel and accessed it both from the wheel well and overhead.
the new one should have antiseize on it- so be careful it stays on the sensor and not on your hands or packaking...

have fun.