Okay guys, check engine light just came on in my 96 3.8L, 189K miles on it. This code says Catalyst system efficiency below threshold (Bank 2) My question is, and I'm afraid of the answer, does this mean my Cat is going bad on bank 2? If it's a bad cat I am not replacing it. I replaced one on my grandmother's s10 and that was a 2 day job for me, and it was at least up off the ground some. Thanks guys.

 

Not neccesarily. What you could do is swap out the post (rear) cat O2 sensors. If your code changes to Bank 1, you know that the post O2 sensor is shot. ) O2 sensors are generally good for 60,000 miles.

 

Hm, my oxygen sensors don't have that many miles on them though. While fighting my check engine light previously (as the previous owners of this mustang beat the **** out of it) I replaced the entire evap and emissions systems, except the cats. I'll try that though if the light comes back on. Thanks.