Ok so here's the next problem with my car. At 4k rpm, the car is at 16psi. The car starts to studder like its choking. From what I have read on here before, I thought it might be the cat, but I don't smell it, and its not bright red after driving. Its not throwing a CEL, does anyone have an idea what this could be. I have the airbox mod done, but thats all. Thanks for the help!

 

If everything else is stock, yeah its the cat.

 

So I assume it will get worse?

 

DEF THE CAT... get ut fixed or hollow ut out and don't drive it hard til you do ask darksun what happed to his... intercooler just popped for the second time now....

 

Yeah, sounds like the CAT to me too. Good thing it is warranty repair.

 

Ok, so an update. After driving home 40 miles on the highway with the cruise on I noticed a few things. First, at 70mph, the gauge reads 5psi vacuum as opposed to 10-12 vacuum while cruising. Second, the engine was running 5-10 degrees hotter than normal. Third, my gas mileage has dropped about 8mpg, and last, it makes a horrible whistling noise when I push on the gas. My guess is from the exhaust leaking out somewhere do to it being clogged. Any thoughts other than the cat? Thanks again!

Also it threw code: P0420

 

Its the cat.

 

P0420 is a low catylst system efficency. Take the car to the dealer.

 

That's gonna be the good ol' catalytic converter... do yourself a favor and take it to the dealership ASAP.

 

CAT,,,, don['t drive it hard til you fix it....

 

yah get that **** fixed now

 

Thanks guys! Its goin to the dealer today for the EIGHTH time in less than a year!