baze

HI readers i have an 01 1.8 with the pes t28 and just tightned all the hoses and all of a sudden the car is pushing like 30 ibls of boost,but breaking up like crazy if i keep it floored,could this be the cause of a bad mass air flow sensor or a bad n75valve? Also i have the stock ngk audi plugs ,could those also be contributed cause? thanks

mAd1(gt3071r)

but yes, even a bad N75 could do it. Do you have a VAG handy? The reason it's breaking up is due to the excess boost. Your ECU is picking up the boost and closing the throtle so you don't blow up your engine. You can actually observe this with a vag and watch the block for the throtle plate angle. When it breaks up, it should return to 0 degrees.

beejohn

30lbs of boost is a bit much, probably running lean = engine blow up.