QR25DE question

[Joelburg at aol.com]

Ok, so my CEL light came on a few weeks ago and I pulled the code for (0221) TPS malfunction, bought a new TB, replaced teh unit. That code cleared and now I am getting code 0507 (+/- more than 200 rpms at idle). Ive followed teh procedures in teh FSM for throttle plate reset, pedal positions sensor reset, and idle air volume learning, all of which are supposed to be done when disconnecting the TB harness. Ive checked over my intake arm (AEM CAI) and have found no leaks. Ive replaced all gaskets associated and still no luck. I have noticed that my exhaust is a little more audible/bassy and it may be that I have a blown out cat, not sure though. I heard my header leaking under WOT and went to retighten it last night and still no luck. Do you guys have any ideas? Heres a link to a tech thread I started that has ALL the information on what ive done so far. I hear you guys are the best so hopefully you guys will know whats up with it.

http://www.b15sentra.net/forums/showthread.php?p=1362500#post1362500