I have a stage 2 with a 2.9 and i was pushing 16-17 psi for months. On my drive home tonight i saw that its only making 9psi to redline every gear. I just changed the oil on it maybe 2 weeks ago and its got 41k. STock exhaust system, And a k&n cai. NEED HELP

 

any funky sounds? sounds like you might have a boost leak somewhere or a bad boost gauge

 

No no sounds or anything. and i thought maybe my boost gauge but it shows up on the interceptor gauge that its only making 9 psi. I also got out and felt my supercharger and it was as cold as ice.??

 

bad boost bypass solenoid or disconnected vac line on the bypass valve.

 

i recently had been only gettin 5 maybe 7 when i had a boost leak at my gauge and car ran like ****... just have to find where the leak is if its a leak

 

Does any one have a pic of where this is under the hood??

 

right on top of the sc... it looks like a little black wastegate... pull off the hose and see if it helps

 

the last time i did that it made it idle really low and it would jump up, and felt like it didnt want to stay running.

Ok i unpluged the one vacuume line from the Sc to the wastegate looking thing and its just it runs perfect. I got all 17 psi's. But wont i throw a CEL ? I did a while ago when i had it off for a few days.

 

as long as you seal off the line you pulled so you dont have a vac leak, you wont have any code.

 

Sounds like a classic case of Intercooler pump failure. When you IC pump fails and the car sees extreme IAT2s it puts the car into a retarded mode different than Limp Mode. Check the IC Pump first before changing any parts.

 

ahh yes. i forgot about the failed I/C pump. but i dont think it pulls that much boost. usually IAT boost is set at 80%. he was getting about 50%

 

i have a question if anyone can help... i noticed a few weeks ago that my exhaust sounded kinda funny and now im boosting like 17.5-18psi.. i have the gm stage 2 kit.

 

yep
Or it could be your intake vac line (or in my case it was a line on my catch can)

clogged cat.

Really? That's strange. I never got that (redline) and I was running without the i/c pump for maybe 1k miles because the relay was detached from the fuse box. Temps didn't get crazy high either. (maybe 165)

 

would a clogged cat throw a cel? and i also put the megan racing exhaust on after this so would it be clogged in the downpipe?

 

Nope (as far as I know). I think the 2nd o2 sensor will still read that there is less exhaust (ie the cat is working) otherwise it would throw probably p0420. It won't be clogged in the downpipe it will be clogged in the "cat body" you're going to probably have to either gut the cat or cut it out and weld a new one on, or get a new head/dp. If you replace the cat go with a high flow cat, vibrant and (I believe) magnaflow sell them also random technology.

 

Safe to unplug the line and cap each side? Long term effect?

 

My buddy has his vac line unplugged for over a year now. given hes tuned for a 2.7 meth and such hes never had a problem. He was only pushing 9ish PSI before he unplugged it.

 

I pulled the line of the acutator, Not the back of the bypass....

the one going from the acutator to the bypass

 

I think that's a bit high for a 2.9 maybe not with the stock exhaust... But yeah...it's a boost leak probably at the vac hose to your intake.

 

It's not IAT boost, it's like a cripple effect. After seeing the problem it wont throw a code but it will lock boost in under 10psi no matter what pulley you have.

 

so when the ic pump fails the ecu will automatically kill boost? did not know that

what i was looking at was the tq management section of HPTuners where it has COT boost %, IAT boost %, etc.