I have a 2006 A4 Quattro. A couple of weeks ago check engine light came on. Took it to a place that pulled 2 codes: fuel pressure sensor (I think P310b) and turbo boost regulator (P0299). I took it for a second opinion and it pulled another code: turbo boost sensor (00665). Had this replaced then check engine light came back on after 70 miles. Took it back in and now only the code P0299 came up which the guy said was turbocharger underboost. Now I'm totally confused. The car seems to run fine. Any suggestions???

 

If your turbo is bad your not going to lose anything besides boost power. Your car will run like it would any other day. On occasion you will get a weird smell from it spooling incorrectly. You should have it fixed though. In the long run its bad to run an engine that comes stock with boost with out it.

And welcome to AF

 

Thanks! So you think if the diagnostic didn't pull up the fuel pressure sensor code for the second time then I shouldn't mess with that and just focus on figuring out what's wrong with the turbo?

 

i would change my fuel filter and look into the turbo issue

 

Hi there - I have a 2007 Quattro and today the Check light came on. I will take it to the garage but would like to know how urgent it is. I added synthetic oil yesterday as the oil light came on but doubt it has anything to do with this light popping up. A coincidence though. Car is running fine, no problem noted.

 

If the check engine light is on and the vehicle do not have a driveablity issue, then it is most likely a faulty emission device.