The car feels as though it wants to keep building but it just maintains 5psi and “lags” per-say. This doesn’t happen all the time. It will be just out of no where mid drive it cuts off at 5psi and has low power. The car isn’t throwing any check engine lights for it and I’ve driven it well over 300 miles. I’ve changed the tubes on the back side of the intercooler as well as the gaskets in hopes it could be a leak but everything is tight.

Have you checked codes? 5-7 psi is wastegate pressure so it's either in limp mode or has ignition problems. Bad plugs or bad coil packs or both (likely). 

 

GD

Yes i did, it’s showing no codes

It doesn't really mean anything - so many of these cars have been tuned (and badly I might add) that you can't trust they didn't go in and delete a bunch of "nuisance" codes - the ones that get deleted most commonly are the misfire codes. Does the car have any modifications?

 

GD

100% stock, one owner car and I know for a fact he didn’t have the intelligence to modify anything to make the car run perfect for 3 months and then out of the blue run like this, like I said, I reset the computer as well and ran it well over 300 miles so at this point if I had a misfire I’d be able to Atleast see it pending.

Check for exhaust back-pressure. These models have catalytic converters in the up-pipe before the turbocharger. Suspect you may have a malfunction in the up-pipe cat. Happens pretty frequently and destroy's turbo's. 

 

GD

Is the turbo making any different noises when it's trying to spool? Like before it was quiet, now it "howls"?

 

Is the wastegate working correctly?

 

Is the BOV stock and working correctly?