Intermittent Rough Idle and Misfire/Stall on 2.0 TFSI.

[JonnyDotNet]

Hi, I'm hoping someone can shed some light on an intermittent problem on my son's 2.0 TFSI B8. It will run fine for a few days and then suddenly the idle will get very lumpy with engine shaking and sounds like it's backfiring through the air intake. Eventually the check light will come on and the car will not start. After a day or so it will restart and everything is fine again. We've had it into a main dealer who couldn't find anything wrong with it. After the last episode I managed to get some fault codes from a mobile test guy which were: P068A, P2279 and P2237. This seems to point to a problem with either a vacuum leak or O2 sensor.

We've just had it looked at by another independent garage who again said they couldn't find any problem.

I really feel sorry for my son who is at his wits end so if anyone has any ideas I'd be very grateful.

Many thanks.

[Steve Q]

Definitely consider the maf or lambda sensor. looking for cracks in the pipes is good too, especially around connectors. 

[Stevey Y]

2 hours ago, JonnyDotNet said:

Hi, I'm hoping someone can shed some light on an intermittent problem on my son's 2.0 TFSI B8. It will run fine for a few days and then suddenly the idle will get very lumpy with engine shaking and sounds like it's backfiring through the air intake. Eventually the check light will come on and the car will not start. After a day or so it will restart and everything is fine again. We've had it into a main dealer who couldn't find anything wrong with it. After the last episode I managed to get some fault codes from a mobile test guy which were: P068A, P2279 and P2237. This seems to point to a problem with either a vacuum leak or O2 sensor.

We've just had it looked at by another independent garage who again said they couldn't find any problem.

I really feel sorry for my son who is at his wits end so if anyone has any ideas I'd be very grateful.

Many thanks.

Hi if it won't replicate the symptoms for a few days then starts again its not an air leak it sounds more like the Lambda sensor going stupid in view of the relatively low cost and ease of change I would try that first.

Steve.