oxygen sensor question?

[scott540]

Hey, check engine light came on yesterday. Stomp test showed 1221. Does that mean both 02 sensors are bad? or just one?. Car just turned 80,000 miles last week. I knew something would go wrong. It seems to run fine- how soon do I need to replace one or both sensors? What's the danger in waiting?

[rickm]

I had mine replaced earlier this year after receiving the code. The only thing that I saw change after it failed was my mpg dropped a few...like 5 or 6. :P After replacing the failed one everything returned to normal.

Maybe Bill or Winfred could chime in but I think replacing both while you're under there isn't a bad idea. If you have an indy who works on your car he might be able to pull the codes to see which sensor did fail.

[632 Regal]

Clear the codes and see if they come up again, my car did the code thing and I cleared them and havent had a code since...some kink of fluke I guess. If you wait and it is bad you will notice worse mileage and sometimes an erratic idle or stalling etc.

[Bill R.]

waiting is that an overly rich mixture will overheat the cats and cause them to go bad... pretty common on the v8 and pretty spendy too... When you hear those cats rattling you know you waited too long...






Hey, check engine light came on yesterday. Stomp test showed 1221. Does that mean both 02 sensors are bad? or just one?. Car just turned 80,000 miles last week. I knew something would go wrong. It seems to run fine- how soon do I need to replace one or both sensors? What's the danger in waiting?

[scott540]

Thanks Yeah, I know the sound. Had and 85 Audi 5000 with a bad cat. Not a nice sound. Wasn't nice either when the PS rack went, the wheel bearing went and the transmission started smoking either