Po299 turbo charger underboost any ideas

Sticking vanes is the most common cause of over/under boosting.

Phil

Sticking vanes is the most common cause of over/under boosting.

Phil

That was my thoughts as my privious audi did the same but other way round overboost oh wel hybrid cuming soon so il live lol

also the black vacuum valve box on top of drivers side inner wing or the pipe from it down to turbo actuator

Edited 25 July, 201213 yr by bluecar1

Yes.

Check all the vacuum pipes.

I recently had some issues and it was the connector with all the vacuum pipes on that was broken and leaking.

Try giving the turbo actuator a wiggle and seeing how free it feels.

There are ways and means of cleaning the turbo out too.

Phil

Probable cause for this code is mechanical fault.

SN