Need advice from the S4 gurus

[EnviedA6]

Ok so I go to drive my car about an hour ago after cleaning it, to go get gas before the hike up the price and noticed that I couldn't boost past 7psi. I was like, "that's strange I normally boost at 17psi". I come back home to see if there's a boost leak....found nothing. Checked my TBB boot that I had replaced 3 months ago and.....nothing. Both turbo's spool the way they normally do but I can't find a leak. Is this ad DV problem or is there something else that I should be looking at?

Anything would help at this point...going to go drive the car again..grrr

[s42k5b]

did you replace your throttle body boot with a samco one?

[boomdaddymack]

any faults in the system can you pull any p codes

[EnviedA6]

Yes it is a Samco TBB boot. Took the car for a test drive and same thing. The car sounds fine, and I double checked for leaks and still nothing. Not throwing any codes, no CEL so at this point I'm clueless. How could this happen over night? Ahhhh this is frustrating

[s42k5b]

Pressure test the system if you havent already

[MAKK]

You don't have the selectable tune through the cruise control do you? Did you buy the car modded or have it done your self?

[EnviedA6]

Pressure test the system if you havent already

I don't have access to a pressure tester unfortunately. I'll have to locate one somewhere. Where can I find one?

[EnviedA6]

You don't have the selectable tune through the cruise control do you? Did you buy the car modded or have it done your self?

Flashed by authorized APR dealer. I do have the option to switch programs using the cruise control but it's still the same thing. It's switching programs but still can't boost higher than 7psi. During my second test drive I was able to boost 10psi but that was it and it only happened one time so I'm still only boosting 7psi

[davism1]

check for hidden codes maybe you need new egt sensors and your in limp mode.

[s42k5b]

They are relatively cheap..ECS,JHM And VAST sell them i think. Ive heard of people making them also..

[EnviedA6]

check for hidden codes maybe you need new egt sensors and your in limp mode.

Hmmmm...limp mode, didn't even think of that but yeah that's the way it feels, like the car was never chipped. How would I locate hidden codes?

[EnviedA6]

They are relatively cheap..ECS,JHM And VAST sell them i think. Ive heard of people making them also..

I'll look into those companies and look for one. Good lookin out bro

[davism1]

You need to scan the car, just bc theres no CEL doenst mean there are no codes.
You can make your own pressure tester for $15 in about ten minutes, just google it.

[MissingPixels]

What did you use to test for boost leaks? How much pressure did you use?

[s4audica]

Seriously it might just be limp mode. Same thing happened to me last week, car started boosting 5psi, I pulled over, popped the hood, check for any soundable leaks, dv's, vacuum lines, found nothing. No CEL, scanned the car, found code for charge pressure control, cleared it, car's been fine ever since. Just a thought, get it scanned.

[EnviedA6]

Seriously it might just be limp mode. Same thing happened to me last week, car started boosting 5psi, I pulled over, popped the hood, check for any soundable leaks, dv's, vacuum lines, found nothing. No CEL, scanned the car, found code for charge pressure control, cleared it, car's been fine ever since. Just a thought, get it scanned.

How did you fix the problem? Sounds exactly what's happening with mine. If I pull the battery terminal off, wouldn't it reset any codes? Just curious to see how you fixed yours.

[davism1]

How did you fix the problem? Sounds exactly what's happening with mine. If I pull the battery terminal off, wouldn't it reset any codes? Just curious to see how you fixed yours.

Go to autozone and get it scanned for free to see what is causing it to go into limp mode, chances are just clearing it without fixing the problem will cause it to happen again.

[b5s4tt]

the best way to check for boost leaks is to find a someone with a smokemachine. it uses babyoil to make smoke and you hook it up to the car, and where ever you see smoke pouring out of is a leak. much easier then a pressure tester. be advised the smoke machine is a $1000 piece so not everyone has it

[EnviedA6]

Ok - checked for codes and scanned for anything that would cause this problem and had them cleared. Went for a drive and.....ahhhhh 17psi hmmmm it's sooooooo nice, smooth and strong like it was. NO MORE 5-7psi!!!!!
I just want to thank everyone for there knowledgable thoughts and opinons. I was in limp mode and it had to do with the N75 valve so once the codes were cleared, everything was fine and back to normal.

THANKS FOR EVERYTHING GUYS!!!!!!!!!!!