[vbmw335]

My car has been overboosting for the last few days even without the procede on. I took it into BMW with just the catless dp's on. they came up with two theories, neither make sense to me...wanted your input.

1st theory: the catless Dp's dont produce enough back pressure and its causing the turbos to over boost.

(doesnt make sense to me, wouldnt the waste gate control the overboost?)

2nd theory: One of the O2 sensors are either failed or not installed correctly causing the car to read the A/F mixture incorrectly and causing over boost.

In anycase the tech seemed less then thrilled to work on my car and told me to return everything back to stock and they charged $125 just to tell me that!

Please advise.

Thanks

[Tuned335i]

Wow. That takes balls to go in with mods considering the stance that BMW has taken regarding mods of any kind, much less powertrain mods!!

[vase330]

Originally Posted by vbmw335

My car has been overboosting for the last few days even without the procede on. I took it into BMW with just the catless dp's on. they came up with two theories, neither make sense to me...wanted your input.

1st theory: the catless Dp's dont produce enough back pressure and its causing the turbos to over boost.

(doesnt make sense to me, wouldnt the waste gate control the overboost?)

2nd theory: One of the O2 sensors are either failed or not installed correctly causing the car to read the A/F mixture incorrectly and causing over boost.

In anycase the tech seemed less then thrilled to work on my car and told me to return everything back to stock and they charged $125 just to tell me that!

Please advise.

Thanks

Why would you do that? They could have voided your warranty if they really wanted to. So I say just do like the tech told you to do. He was not amused because you are making his job hard. He is supposed to flag you, but instead he was nice and asked you to take it off. You know they might be right too about what your problem is. I'd take the pipes off and drive for two days and see if the problem is still there. If it is, take it in then.