Hi,

I'm hoping someone will be able to help me with this problem. I have 2001 Jetta wolfsburg 1.8T.

Few weeks ago i had this strange problem where when the car was idle it almost wanted to stall (i was told its called rough idling). the next day my engine light came on with the following error code p0172 Bank 1 too rich and P1296 Feul Air metering. I had it checked out and the Mech said it could be o2 sensor or or MAF. He said he did some diagnostic and charged me $79 (Although now i think he did absolutly nothing). I got a Bosch MAF sensor and replaced it myself. But the problem is still there.

The problem is very intermetant and some times it happens when i turn on the car and let it wormup. Some times i could be stopped at the stop sign or red light and sudently it starts choking. THe strange part is when i gas it to keep it alive the first few times its does nothing, until finally after 5 or 6 times the rpm shoots up. The rpm is usually a little under 10k when its idle but for some reason suddenlty it just drops down to about 5k and theats when the rough idling occurs. I have no clue what the problem is. I dont know if it has to do with teh fuel pump (but then again why does it only happen when i'm in idle) Could it be the fuel injector? I originally thought problems like that occur vary rarely when using higher octane gas such as 89. If anyone has ever experienced this issue can you please let me know.

Thank you!

 

can a bad o2 sensor be causing rough idling? If so is there a way to find out if its the sensor before the cat or the one after?

Thanks again!