A couple of days ago I drove my car and the boost would not go past 5 lbs it would fall on its face completly. then today I took it out and it worked fine. then I washed it and put coolant in it. then the problem started again. the motor is warn but it does not smoke starts fine and idles perfect. I only have a down pipe mid pipe and a catback exhaust and intake on it. other than that it is stock. what could it be??

 

I dont have an intake but have a down pipe, mid pipe and cat back exhaust. My car only boost up to 5. I'm only using the mid pipe because a friend is borrowing my stock cat and it's not good to have 3 inch piping with out all the other mods(ecu, etc.) I have heard you can blow the motor that way so i'm not really driven mine right now. But its still boosting 5 with or with out the mid pipe. I recently swapped my twins to somewhat a better set and then that when it all started. Old set use to leak but the set i have now is still not that great. I would check all the vacuum hoses and piping. You also feel better acceleration with the stock cat with the dp and cat back.

 

Could it be a ground? or a turbo? it seemes like it is something electronical. what things should I check?