ndauderman

I have the same problem at 127K miles. I have an after market exhaust with the same Y and 3 cat system with the sensors in identical locations. Nice improvement in the exhaust system . Recently, I replaced both cats off the manifold thinking they were the culprits of the threshold issue - unfortunately, the light came back on :chairshot: . How can I test the oxygen sensors? Any idea what my next steps should be? I will need to pass smog in the next year, so I would like to resolve this. Thanks.