My 96 Monte Carlo has recently had the fuel pump replaced. When it was in the garage my mechanic told me the 02 sensor code was being shown. It drove fine for about a week after and then started to cough and sputter while accelerating. At idle it was fine, also what i thought was a valve tap was so loud you could here it while driving with the windows up! Now this morning though while taking my girlfriend to work i noticed at idle it was shaking terribly and feels like it wants to shut off at idle. When i get to about 1,500 RPM though it seems to run fine, and also something very strange, the loud tapping noise just all of a sudden stopped. I thought maybe the MAF sensor and i unplugged it and it does seem to run slightly better with it unplugged. Does anyone have any idea what is going on? I was told i have 2 02 sensors and with the code being shown last time i was at the garage that could be the problem. But after that almost $400 bill i cant really afford right now to take it back to the garage. Thanks for reading!

 

if youre showing a code for both bank 1 and bank 2 o2 sensors its your maf. this is confirmed by it running better when its unplugged. you can try shooting some maf cleaner on it ($7.99 a can) or a new maf for your car is about $85. please for the love of god dont pay a shop $400 to change the maf, its held on by two worm clamps in your intake duct and you can do it in about 5 minutes. id try the cleaner before you start throwing parts at it, but you can do the maf and the 02 sensors yourself and a tune up and still be ahead of paying a shop for the maf. gurantee it runs like new after that.

 

Ok thank you very much for your input. I plugged the MAF back in last night and it didn't actually seem to run any different, maybe it was in my head but I could've sworn it ran better with it unplugged. I'll still grab a can of cleaner this weekend though. I'm gonna call my mechanic and see how much he'll charge to run a code diagnostic on it again and get his opinion and then go from there. With me plugging it back in and not really seeing a difference I'm not so sure if it is the MAF now. Thanks again!

 

I talked to my mechanic and he said that the 02 code that was being shown was for something about the way it heats up? He said it will take longer to heat up but should be working ok. He said it might run differently but what I described to him he said might not be the problem. He said my EGR valve code was also shown and that could cause the rough idling. He said I could probly change it myself but I've never done that before. Getting my codes read agin tomorrow again to see what's up.