My girlfriends 2002 Pontiac Sunfire 2.2L keeps acting up.....check engine light keeps coming on O2 sensor malfunction is what we were told, had it reset but came on again.
Every once in awhile the engine revs real hard and seems to go away ? Any possiblie ideas on what this could be please help!
uh i would imagine if you keep gettin an o2 sensor code that maybe your o2 sensor needs to be replaced. Its common sense
It could be more in depth but get the sensor changed and let us know if it still happends.
A good tuneup probably wouldnt be a bad idea.. all filters n fluids and clean throttle body
and a seafoam treatment
Yes that would be my guess as well, Wornout O2 sensor.
Dont change your O2S... First what is the code exactly, secondly why is your engine reving up when its not supposed to. Dont change your O2S without have someone check the waveform on an ocilloscope. Oxygen sensors dont just wear out, the can get damaged and need replacement, but it wont just wear out
Chris
99 Z24
"Remember the days when sex was safe, and Racing was dangerous?"
Uhh duh I kinda knew it had something to do with O2 sensor...... Can't explain the revs? Will have it re-run tomorrow.....will keep ya posted. Thanks for the info.
People on this site can be really dumb sometimes.
Just because you have an O2 does not mean the O2 is bad. In fact more often than not it ISNT bad.
For exaple iif the car has a vacuum leak, a small one. The car will be running lean and the O2 sensor will see, it say will lean go rich, LT/FT go up up up.....okay now maybe after a few weeks the leak gets bigger, more and more air, and O2 sensor keeps seeing it but it can no longer compensate, it has been maxed, out as is LT/FT. Okay now the computer will see the O2 sensor giving a high voltage above 500mv all the time because of the lean condition, it is going to say go rich all the time.
The computer sees that as the O2 sensor hasnt switched on me, I'm telling on it. So it sets the CEL.
So actually if you people want to make Bosch and other people rich by throwing parts at a car, go ahead.
I perfer to diagnose problems instead.
I hope you people stop posting such bad advice all the time.
- 2004 Cavalier - 124k, owned since new
