So I have owned this car for about 2 months now. I bought it used with 40k miles on it. It has a Cobb Downpipe, Cobb short ram intake, lightweight pulley, and a turbo timer. I was also told that the car has been pro tuned. Car has run strong since I got it. So here is my problem, I took the car out for a cruise on Friday night and the car was running perfect and nothing out of the ordinary. The car was low on gas and the gas light was on.
I next drove it Saturday and I filled up with gas. I didn't try to get on it at all until after I filled the tank. When i went WOT the car would only reach about 8-9 PSI. Once the car got close to redline it would go up to about 12 psi but it took a lot to get there. My first thought was i put the wrong gas in or it was bad gas. I go it down to about a half tank and topped off and dumped in some octane booster and drove about another 50 miles and there has been no difference.
I have tried a few things to troubleshoot this but have not figured it out. I checked all of the turbo and intercooler connections, cleaner MAF sensor, remove air intake and cleaned, remove boost solenoid and cleaned with carb cleaner, removed wastegate tubing and checked to make sure the vacuum pill was still there, cleaned the vacuum line and took the pill out and re installed, disconnected battery to reset ECU. All of these had no effect on the car's performance. I am lost as to where to continue now. I found all of these ideas on the forums of things other people recommended trying. Any help would be really appreciated. Thanks!