Alright guys, so here's my story. I have my boost set to 16 psi and it was dropping consistently after 4500 rpm to 12 psi by redline. I had boost leaks in my throttle body which I recently fixed. I thought the problem was solved but I still can't hold till redline. I drop to about 13.8 psi so it's gotten better but still not 100% resolved. I have an evap smoke machine which I use to test for the leaks. My question is this. I have the stock exhaust with an aftermarket downpipe which replaces the main cat and one of the precats. One of the precats is still there. Could this be my problem?