I'm currently running full-bolt ons along with a custom tune and a cobb bpv (currently set to 50/50 recirc). I recently had a boost leak test and they told me I have a slight leak. Right now my main problem is the engine seems to stumble here and there at low rpm's and low boost/cruising with slight load. On rare occasions I experience surge/stutter at low rpm's when I let off.

Im guessing it's the bpv..should I tighten or loosen the spring?

 

Noone?

 

Have you ruled out all other potential causes of the boost leak?

 

They found that one of my couplers were bad so they replaced that, and they told me that my bpv was leaking slightly.