P0299 Underboost code - diverter valve?

[wildoolittle]

Hello all,

My first post so here's a little background. Just became the owner of a 2012 A5. I'm experiencing a couple problems: 1) the car doesn't seem to want to really boost until about 3500-4k. 2) the previous owner installed a AWE diverter valve. 3) there's a check engine light #P0299 for turbo underboost.

Now, here's my guess. The diverter valve is making a loud blowing noise everything I release the gas (I thought it had a BOV all this time...). Could a torn DV be the culprit for all the above? For what it matters, the car is also running an AWE exhaust and Injen cold air intake.

Thank you in advance and yes, I know that there are a post or two that are similar but please help me here nonetheless.

[Sgibb16]

http://wiki.ross-tech.com/wiki/index...3/P0299/000665

[wxsgt]

it is possible that its the Diverter valve, but a dirty maf if you are running an oiled filter can also cause it. if you want to go cheap first(DV's are too bad if you go oem) get some maf cleaner and make sure thats all good, then jump on the DV. I had the same issue replaced the DV and still was getting the error, cleaned the MAF and nothing since, I use a K&N Oiled filter in my B8A4.

[wildoolittle]

Thank you for the advice guys. I wish there was a more specific code... everything is such a puzzle in this car.

[osugsxr]

had the same code swapped out the dv and everything seems to be good no codes so far