CEL P0299 code help please!
 

Newbie here, I have a 2005.5 a4 2.0t. The check engine light is on and the code is P0299=low boost. I have checked for air leaks and found nothing. The car seems to drive fine, maybe a little power loss, not sure it is my wives car so I only drive it every now and then. I dont know what to check next? Is there a sensor that commonly goes out on these cars causing the low boost code and cel? What should I do next??????

Any input is greatly appriciated.

Thanks in advance,
Donnie

Anbody????????????

P0299 Underboost is a commone CEL for when a diverter valve goes out. The stock diaphragm diverter valve is prone to tearing after a while. I got that error code and had only a slight tear in the DV.

It is really easy to check and/or replace the DV. It is located on the front side of the turbo. It is an electric DV, so there is an electrical connection running to it. Once you take that off, it is just a matter of taking out 3 hex screws and pulling it off.

The best part to replace it with is the new design for the B8. That part number is 06H 145 710 D. The cheapest place I found it was genuineaudiparts.com.

HTH

Thanks, I will look into that. How much did the new piece runya, and how many miles when you had the problem?

how can I tell if its cracked????

You can tell by looking at it. There will be a green diaphragm and it will have a tear in it if there's a problem. I had 65,000 miles, although a lot of them have torn earlier than that. I got mine off of the website that I mentioned. 70 something bucks.

im having the same issue can you please take a piture of the DV valve so i know im checking the correct part. sorry im not top savvy when it comes to cars.

I would like to see pics also!!!!! any updates donnie?

Old post.... I have the same issue, P0299 and P0420, low boost.... They replaced 2 DV's and the car is throwing the same codes. Audi said it now needs a new turbo and cat, I doubt its the turbo but a bad cat would make more sense.... too much restriction causing the turbo to not spool as it should. Any input on this?

I am currently having the same code with my 2006 2.0T, its in the shop tonight getting a really good once over. A possible sludge problem could be the culprit in mine ... will know more tomorrow. I would rather it be a cracked DV, a loose hose, or something very simple.