So since I haven't got the cash yet to get me a scanner that can scan for KR. I settled for now with installing a cheap-o sunpro boost gauge to at least check how was my infamous 98 GTP flowing and to my surprise, It's doing up to 8.5 or so psi at 5,500 rpm on the 1st to 2nd shift and a bit lower (around 8) on 2nd to 3rd gear.

The only minor mods that I have is a Ubend delete, 185 Tstat and a 4" CAI, everything else is bone STOCK. I've been reading around for stock psi on these cars and I belive it should be 5-7 at shift points if it was flowing right.

So my first question is if 8.5 psi ok or there's something wrong? If there is, I suspect the CAT may be clogged is there a way to check if it's clogged?

Thanks!