A vacuum leak. What does the vac/boost gauge read at idle? What does it read during deceleration? If the gauge isn't getting almost pegged to the left, you have a vacuum leak.

When you removed the fuel rail, you removed the vacuum tee from the fuel pressure regulator. I have had that tee crack on me a few times. Re-check all vacuum lines.

greg b.

Well, I still haven't figured out my problem. i finally took it to the shop and they're trying to tell me its a plugged act. but for some reason i have my doubts about that. I mean' would that affect my boost? what code would that give? they want more than a thousand bucks to change this. I think that is excessive even if it the problem. HELP!

act was supposed to be cat. seems i cant edit :(

A clogged cat will cause problems like a misfire because the exhaust can't get out. A grand to change a cat is robbery. A new cat is about $70, and perhaps $100 to have a muffler shop weld it in.

Thanks Danthurs, now, i was looking thru some old posts and there seems to be a cat that supposedly will fit w/o throwing any codes, goerlich or something like. would that be the one that i should use? This forum is the best thing since sliced bread, lol thankx

Yes, that'* the one. Sawgunner should have a URL for that one

How old/how many miles. Poor running beyond an idle and "instant boost pressure" makes me think clogged cat.

Sorry to leave you guys hanging. Well, it turns out it was a plugged cat. thanks to all who replied.

Good to hear, hope it didn't cost you to much.