hi all. i was driving my truck (2004 chevy 1500 4.3) one day and the engine light came on. just happened to be the day after i got it back from the transmission shop. brought it back to them and they hooked up their computer to it. told me it was an O2 sensor on the drivers side. their computer couldnt tell me if it was the upper or lower one. got a new O2 sensor and replaced the upper one before the catalytic converter. had my brother take it to advanced auto parts where he works to have the computer reset. he said when he hooked his computer up to it he got a code saying that it was either an o2 sensor or my cats but the computer their couldnt tell him which side. he reset it. drove 45 min that weekend headed to NH and the light comes back on. truck started to show lack of performance. had him take the truck into work and have it checked again. this time he said it was a different code telling him and his buddys at work that the computer was saying that it was the passenger side but couldnt tell if it was an o2 sensor of cat. im paying almost $80 a sensor. i just picked one up last night and will be replacing the passenger side one before the cat. if the light comes back on and the code stays the same then ill replace the next sensor after the cat on the passenger side. if this continues i suppose ill replace the last one on the drivers side. after $320 later and the stinkin' light comes back on i will just go ahead and buy to new cats from Magnaflow for about $60 a piece. has anyone come across such problems as i am running into right now. apparently there is no computer that is able to pinpoint the problem and getting different codes each time i have it checked out.

 

Welcome to the forum. I feel your pain. It sounds like those you're depending on to help you are failing you. What exactly are the trouble codes (without some third person interpretations)? Statements like "either an o2 sensor or my cats but the computer their couldnt tell" is worthless where OBD is concerned.

 

i couldnt tell you off hand what the codes are. as of right now the engine light was reset. tonight im putting on a new o2 sensor. and will find out soon if the light comes back on.