I was doing 55mph and I wanted to pass someone so i started to give it some gas and I wasn't really pulling so I floored it and still wasn't really pulling, so I check my gauge and its reading around 7 psi. I'm chipped and I was around 16 before. In second gear I floored it and the gauge went up real slow til about 6 psi. Now, I've had a check engine light on for awhile, the code is for main catalyst below threshold. What are some possible causes for this boost isue and what can I do to get it straight. I'm gonna do the cat soon, but I'm going on a long trip (without the car) so I'll address that when I get back.
thanks guys.

 

hey man, im new to turbo'd vehicles, but i know a bit about cars in general. here would be my guesses from most likely to least likely

1) you have a boost leak somewhere

2) your failed catalytic converter is actually clogged and you cant build up boost because your exhaust isnt escaping fast enough (backpressure)

3) you had your car serviced at the dealer and they updated your ECU software overwriting the APR tune (i think i read on this site that this happens sometimes, otherwise i might be making this one up)

4) you have APR ECMS (Enhanced Modular Chipping System) and deactivated your APR tune using the cruise control buttons


just my 2 cents, hope you figure it out...