Hey everybody, I really hope somebody can help me out. I have a 2004 a4 and I have an APR chip, KN intake, and forge hybrid valve. The other day, I had the stock resonators taken off and replaced with pipes, and also took off the stock mufflers and put on magnaflow turbo xl mufflers. Car sounded great. After about 2 hours of driving I turned the car off, I came back out and went to drive again and the turbo sounds like its spooling up a million miles an hour, and real loud. Then the check engine light comes on, I take it to the garage and they said its running lean, not enough gas to air. I was wondering if anyone can help me, why would the turbo and the check engine light do this only from changing the mufflers and taking out the resonator??

Thanks for all your help

 

It shouldn't do this. Go to autozone and get the codes pulled and post them back here.

Check for loose hoses and boost leaks.

 

Thanks I will get that code, and I did look for leaks but cant find any, Im prolly not looking in the right places. And it also only makes the sound when I drive, not when its in neutral and I rev it.

 

Thanks for your advice man found the problem