Hi everyone. I'm new to the forum, hoping I can get some ideas of whats up with the WRX. I have an 04, gutted stock UP, 3rd cat delete, Cobb stg1 93 octane. Last weekend I put on a BPM turbo inlet, and now when I start the car up, it kinda lurches/jerks. Then it idles really rough, kinda feels more than sounds like a grinding and theres a noticable shake in the hood. It is not the normal boxer shake. Sometimes it goes away and it will idle fine. As soon as I start moving it runs better, builds boost fine, revs to redline, all that. When I turn the car off, it REALLY lurches/jerks. When Im driving along I kinda hear a rattling sound, but I dont think Im knocking/detonating at all. No CELs at all, checked with the AP too. Im really thinking vaccum leak, but it looks like everything is connected on the inlet. Im worried that I am leaking somewhere and running lean, but no CELs is making me second guess myself. Anyone have any ideas of why the turn on/turn off is so rough? How do I search for the leak? Any help would be great.