Thread: HELP! Sputter Under Boost (feels like missfire)

Is any black smoke coming out? I had the same problem but i had black smoke, i disconnected my MAF and punched it a few times and the problem was gone.

Originally Posted by DanGTP

Video of the bypass? It should be open (up position) at idle and closed (down position) under boost or with the car off.

The BBV bounces when the car coughs. However, it does not do this much in neutural or park, so it's hard to get a vid. Usually the car hesitates while I'm in drive and get on it down the road

Originally Posted by batman1988

Is any black smoke coming out? I had the same problem but i had black smoke, i disconnected my MAF and punched it a few times and the problem was gone.

No black smoke. The car literally drives perfect until I get it into boost. Thats when it studders like I'm revving out off the limiter, but the rpms will slowly bounce thier way up through the powerband.

Disconnect your MAF and go for a drive, build up boost a few times and see if it goes away. If that is not it, i would check for a vac leak. I could be wrong.