Ok, I just got my wifes car back from the dealer as I took it there for a ck. engine light on and a lack of boost. The tech found a secondary air injection code and stated the "blow off valve" which I think he meant the "diverter valve" (the plastice valve that sits on top of the engine just behind the valve cover on the drivers side of the car) that is tied into the air intake. He said that was stuck open and not allowing the engine to boost. He said he tapped on it a few times and the engine began to create boost. He said the part number was 034 145 710 c. He also found these two hoses either soft or leaking and needed replaced, hose 1c0 145 718 c, 06a 103 221 bh. He also found another valve that he called a "diverter valve (part # 06a 131 229) that would not hold vac. and would slowly leak off. I belive the tech just has his terminology wrong and is calling the "diverter valve" a blow off valve (which is the part that was causing the light and no boost condition). The tech stated after he tapped on the part # 034 145 710 c the car ran great and has not had any issue since. I want to replace this part, is this not the "diverter valve" or is he correct in calling it a "blow off valve. I just want to buy the right part. Also, are their any after market diverter valves out their that are cheaper then 75.00 bucks he quoted that work good? If someone can give me a run down on the parts numbers I provided that would be a great help! Sorry this is so darn messed up!!! Last but not least what is the n72 valve and where is it located? thanks!