Quick question for passing emissions...where is this o2 sensor located at. My car is CA emissions, so I believe there are three total. I need replace this ASAP, as I have 2 weeks to get my car to pass. I can remember seeing a diagram of the o2 sensor locations/replacement instructions somewhere, but I cannot remember where. Thanks

Josh

 

i dont know if the placement is different for the CA ones but there are 2 in y pipe (comming from each side of the block) and then another one just before the cat or after I forgot.

 

Josh,

I have been through this problem before and just like you I reported that I have a Cali spec'ed car and have only 3 O2 sensors. Several of the fine guys here thought that I should have 4 O2 sensors.

Depending on the build date of your California spec'ed 1999 car you either have a 3 or 4 O2 sensors.

The problem that I had to contend with was the O2 sensor on the Y-pipe also called downstream O2.

Get your VIN and take it to the dealer to get the right length of the wire harness.

stglock

 

Thanks for the reply! Does anyone know which of the 4 my bad one is (Bank 2, sensor 1)? It's too expensive to have a mechanic change one sensor (like $390), so I just need to know which one it is. I'll freeze my a$$ off in Chicago changing it, but better the money in my pocket than theirs. Any other help is greatly appreciated...I have two weeks to fix this!