I just purchased a 2007 A4 two weeks ago and am thoroughly enjoying it. For those curious, it is black, has the 2.0T engine, Quattro AWD, 6 speed manual transmission, Audi MMI, and the S-Line trim package. It definitely beats the 1997 Camry I was driving for the past decade. Anyway, I am wanting to get the ECU flashed with the APR Stage 1 software. I have done some research and found that the stock diverter valve (DV) isn't really up to snuff when it comes to holding anything beyond stock boost levels due to it being made out of plastic and rubber and that it is best to upgrade it to one made of sturdier material such as steel or aluminum. I found an upgraded OE version of the DV at ECS Tuning that is made of steel and aluminum. I was going to get that when I found one from Forge on the same site that claims to be a BOV and DV in one. I really dig the "psshhh" noise you hear from turbo charged cars, but am leary of buying it if it is going to throw CELs on me after I install it. My question is this: should I stick with just a regular DV made of steel or aluminum or can I purchase the Forge unit and have it serve the same purpose? Furthermore, will the installation of the Forge unit cause any issue to the motor since the air isn't being recirculated anymore and is just being expelled to the atmosphere? Thanks in advance for the response.

 

Stick with the piston-driven OE replacement. I think it's the "F" revision.

 

Thanks for the advice. I think I will stick with the upgraded OE version of the valve like you said. Besides, I don't think my wife would care for the "psshh" noise much.

 

Al least a "D" OEM valve. Unwanted venting is a No No.