I have joined this board because i have actually gotten a lot of help with this so far but now I am stuck. I have a 2000 MC with a 3.8 and also a K&N filter. It has been throwing codes (O2 sensor) since the day I bought it 3 years ago. No big deal, it was still driveable. 2 weeks ago, it started stalling and not starting and I took it to the shop. Couldn't figure it out so they replaced spark plugs and wires. Took it home and it stalled again (right in the middle of driving, when I slow down). Sometimes won't start. It wasn't originally throwing a code when it first started stalling, but after the plugs and it stalled it said MAF/VAF circuit. My boyfriend had the bright idea of unplugging MAF and no more stalling. So we ordered a new one. Put it in, and now its stalling again. Any ideas would be appreciated. I read IAC, could this be the problem. He checked the fuel pump too and is going to see if exhaust leaks. I can drive it now but I need to have it fixed. Also cleaned the air filter.

 

Sounds to me like an O2 sensor is or has failed.....when he gets the exhaust checked.....Have them test the O2 sensors...(theres 2 of them)....coudnt hurt to remove the IAC and clean it as well... how many miles is on it?.....

 

95,000 miles. Have had 02 sensor codes since day one, and I know he replaced one. Could it be the computer???

 

Maybe

Any other check engine codes?

 

mine was a IAC valve and not the o2 sensor but it would say that it was the front o2 (upstream O2 changed 3 times) .Took a while to chase it down but after live scanning the car so we could see how everything was running it was just a stupid 45$ IAC.
And it fixed mine for good . Make sure you disconnect the batty before you install the IAC .

 

Thanks, I am going to try the IAC valve next. There were also instructions that came with the new MAF that says I have to reset the car, not the codes (which we di) and that a dealer would have to do that. We unplugged the battery for an hour to try it ourselves but it did nothing.

 

First off, throw away the K&N. all they do is coat the MAF in oil. Second, what are the exact codes? Many things can cause an O2 code without the O2 being at fault.

 

Yes dump the K&N just causes that exact problem....

And dont forget when u disconnect the battery it may also clear your O2 code....

 

Yea... careful with the oil on the filter. It will affect your MAF greatly

 

Maf cleaner cures k&n oil issue. I haven't had a problem with mine yet , in either of my 3800 cars. Clean your iac then measure the pintle I do believe it should be out 1 1/8 of an inch. Also the front o2 sensor helps tell your cars computer how much fuel to use.