For a 2G, do O2 sensors matter?

[ADLER]

I think my 2 O2 sensors in my downpipe may not be working properly. Does this really matter? Other than getting a CEL, which I can turn off, will it affect timing or fuel?

[detpac]

It does affect performance. The computer is not getting a correct signal so It does not adjust the fuel or timing well. You should notice poorer gas milage and less performance.

[ADLER]

that's what I thought, but some people have also told me that the O2s are basically for emissions only, and won't really effect anything....

[dj4play]

for tuning purposes and engine management you NEED wideband o2s. The stock ones are only good for emmisions control on your computer