Quote Originally Posted by Wakingcrow View Post
You should easily be able to tell if the rubber tee is bad - maybe try water at the joints. The Evap solenoid leak will be slight and only give more slight misfires - not like what you described. (And I certainly don't thing it needs PCM reprogramming).

2. I sprayed brake fluid around the sc and engine top according to a video and engine didn't try to stall.
3. It doesn't misfire under idle or even when revving at idle, but sometimes does backfire after rev.
4. Seems to only happen at the same time boost engages, but I don't know if that's a chicken or egg.
5. It's def not the cat, because there is none, just a pipe. Been like that for a long time before all these problems.
2. Was that "engine top" for checking vacuum at the S/C bypass valve (solenoid) lines? This is located on top of the S/C toward the front of the engine.
3. That backfire sounds normal - I always get 2 misfires
4. (redundant) Check vacuum lines at that boost bypass valve. (I recall it being easy to mess those lines up.)
5. Maybe the O2s have gotten dirty. (for saving money and not remove-and-replace method of fixing, O2s supposedly can be cleaned with something like SeaFoam - of course, there are completely conflicting opinions).