Hi I own a 1997 2.5L TL that wont pass smog because the oxygen sensor is bad. According to the smog tech it is the pre-catalytic converter sensor that needs to be replaced but I read up on it and it doesn't seem that hard to do on my own. Can anyone tell me which sensor is the PRE-Cat one and where it is located? I'm also not sure if a two wire sensor is ok, or if I should spend the extra money for a 4-wire sensor. Any suggestions would be great.

 

It's below the exhaust manifold on pax side. You'll have to remove the battery and battery tray for access.

Was NOX high? If yes, then new O2 sensor won't fix the problem. You need to pull the EGR manifold and clean. I had to do this on my 97 2.5TL.

Any Check Engine Light, codes?

good luck