altima O2 sensor-HELP

[glen1234]

2005 altima 4 cyl, 60,000 miles. About 5 mo. ago check engine light came on. Driving the car fine, but gas mileage sucked. Took it into dealer and they said O2 sensor and air/fuel sensor (upper one) needed replacement --$500 or so. Took it to indep. and they replaced yesterday both for $325.00. Check engine light went off. Today light came back on! WTF!!E@#@. Were they supposed to clear self learn codes?? I mentioned this and they were dumbfounded. He said that after a few starts ECM would reprogram itself. I just disconnected battery in hopes to reset ECM.

Any thoughts please.

[RICERMAN]

I think the computer will reset itself after it cycles though what is called its preset loop. If the light has come back on you need to have it scaned for the trouble code. I would take it back to the place that fixed it and ask them to scan it for free. Thats too much money for a simple fix that didnt fix it.

[garthog]

you could be going through what i went through and that really sucks. my car did the same thing... no matter what i did, the light wouldn't go off until i got rid of the pre-cat. it was breaking up and blowing into my engine. thank god i got to it before any damage was done! sounds like you're gonna keep blowing those o2 sensors until you do something about the pre-cat and i would also have your heads checked and cleaned to be on the safe side. i got some headers and got a thurough check and everything turned out ok and now i have over 100,000mls on it.