jgerma01

Hey guys i know there have been a ton of threads before this with this issue but I needed some help. Last nite car went limp with no boost and today threw a P0101 code. When i turn car off and back on i get full boost back (19-20lbs WOT with gms1 tune) but after a little bit of driving same issue and i lose almost all boost.....I am hoping this is just an MAF issue and not a leak somewhere....also I have a catted dp from hahn, mpx catback and a k&n sri (not tuned for) im also thinking the K&N maybe is the issue but ran perfect for the first few months
Any advice or suggestions wiuld be much appreciated, I already ordered a new MAF so we'll see if that takes se of it
Thnx again

Snail_SS

iTrader: (3)

That code is usually a boost leak

jgerma01

Ok thanks but if it was a boost leak would i be able to hit 20lbs on multiple runs at WOT?

ECaulk

iTrader: (6)

It most certainly could, you're just working the **** out of your poor turbo

umrdyldo

iTrader: (1)

The internet will tell you it's your MAF sensor. But we have seen so many people with the P0101 code that our first response is always boost leak.

Boost leaks can range from very small to your charge pipe blowing off and it sounding like a jet engine under the hood.

You need a boost leak tester to find the leak.
https://www.cobaltss.net/forums/how-...ss-lnf-223319/

jgerma01

Thanks guys....was hopin it would be an easy fix like an MAF.....as soon as temp dropped issue came up.....maybe crack in one of the charge pipe or end tanks on intercooler. Would the K&N sri have anything to do with this issue? Didnt tune for it when i installed it 2 months ago

umrdyldo

iTrader: (1)

It's possible you didn't tighten the intake down well, but don't over tighten it. Just recheck it.

My suggestion for everyone is to get some way to log the car. I use a bluetooth code reader and my phone to watch what the car is doing.

If you watch your fuel trims you should see a change if you have boost leaks. Your car could be running lean or rich due to the boost leak. I forgot which.

ECaulk

iTrader: (6)

lean under vacuum, rich under boost

jgerma01

Yes i have a bluetooth OBD reader....on my way home from work tonite ill watch the fuel trims at idle and under throttle.....anything else i should look for? As per my RPD the AFR was normal 14.5-14.8 at idle and ill def double check the intake hose to the turbo to see if maybe the clamps got loose
Thanx guys appreciate the help

jgerma01

Well I just drove car home and had normal boost(19.6 peak at WOT) the whole way home and no CEL. I also monitored fuel trims thru Torque app....at idle LTFT was 14 to 17 and around 11 at WOT and STFT was rite around 0 +/-2 at idle and got up as high as 10 under throttle. What do you guys think?
Thanks again

umrdyldo

iTrader: (1)

An LTFT of 15℅ is very high. It should be around 0-5℅ sounds like a boost leak to me. I would stop going full throttle until you figure it out. Just for reference 15℅ is close to setting a lean code.

Check the intake then do a boost leak test

jgerma01

Yea it was 15 after I installed the K&N intake which i think is throwing the fuel trims off....i heard the position of the filter can help with that...i think i put mine with the metal plead at the 1100 position...maybe ill try changing the position to 100 and then do a boost leak test

ECaulk

iTrader: (6)

and get some maf cleaner and clean the maf, if the K&N was over oiled that could be messing with the trims also.

umrdyldo

iTrader: (1)

The metal band on mine is at 11 oclock. I range from 2-5% untuned.

Check all connection. Check connection at the filter, check the connection of the hose that comes into the intake, check the connection at the turbo.

If you want a quick check, put the stock intake back on and see if your LTFT goes back to 0. If it stays up then you can pretty much bet on a boost leak.