So for some time now, my boost ( pcm controlled) for some reason would peg at 20 when the engine was cold to warm.
When hot, it would sit at 15PSI. Due to the fact I was spraying WI, if pulled fine.

Well this weekend, and today, I swapped from a dual to a single exhaust pipe, and it didnt line up right.

Following the exhaust to the front, I found a BIG ASS leak after the cat. The bolts were siezed up tight, but there was about 1/8" of play in the flanges.

Basically when the ezhaust heated up, the boost was able to hold steady since the PCM had a handle on the backpressure. ie the heat expanded the flanges so they sealed good.

I had to cut the bolts off and put new ones on. Boost is rock solid.....hehe

me= dumbass for not noticing it.