exhaust leak cause boost creep?????

[97gsssst]

I am currently running a b16g and just a cat back exhaust and when it is cold I am hitting fuel cut like crazy. The boost starts out at 15psi then by 6k it is at 19psi. Could this be exhaust leak which I have really bad coming off the turbo or like my homemade bc.?

 

[steve]

Boost creep is usually caused by more backpressure in the wastegate passage than in the exhaust passage, so when the wastegate opens the exhaust continues to exit via past the hot wheel rather than out the wastegate causing the boost to continue to rise. Porting the wastegate and O2 housing is the typical fix.

It's possible your MBC is malfunctioning. Try running direct from the compressor outlet to the Wastegate actuator and see if it still creeps. If it does, then it's the wastegate/O2 housing. If it doesn't, then the MBC might be bad or it may be because your not building the exhaust pressure you do with the MBC giving higher boost.

Steve