Turbo not working, but car run's fine otherwise, cold air intake whistles loudly


New member
GTI MK7 2015 Autobah
Hi All,

My 2015 GTI's turbo is not working at the moment and I can't figure out why :(. I believe it's electrical or has something to do with some computer though.
This started when I was accelerating in 6th gear at highway speeds. It boosted like normal but then had a thunk and the turbo went off and has never turned back on again.
I've look under the car and under the hood after taking off the intake and don't really see anything wrong. The car still runs fine and there's no smoke or weird noises. I have an Accessport V3 and I can see through their the turbo is still spinning, but it just won't supply more than 4 PSI.
The cold air intake still whistles. Maybe a little louder than normal but I'm not super sure on that.
The car is somewhat modded with a catless downpipe and a stage 2 tune normally boosting up to 32PSI.
I was able to pull some codes from it with the accessport.

Right after the turbo kicked off some new codes popped up:
C2702: Excessive air inflow
P0300 to P0304: All 4/multiple cylinder misfires detected

I drove it a bit more the next 2 days and some more codes:

P2004: Intake Manifold Runner Control Bank 1 Stuck Open
P2015: Intake Manifold Runner Position Sensor/Switch Circuit Range/Performance
P0299: Turbo/Super Charger Underboost
P0068: Throttle Position Correlation

And there are some codes that are always there. I'm including these because I still somewhat suspect the computer trying to be smart about a non-issue:

P0131: O2 sensor circ.Bank1-Sensor Low Voltage (because that sensor is gone after catless downpipe mod)
P0196: Engine Oil Temperature Sensor Circuit range/performance (I believe just a broken sensor, oil level is always fine and coolant temperature is always fine)
P0198: Engine Oil Temperature Sensor Circuit High (same as above)

Has anyone dealt with something like this before? I do have an accessport and I was wondering if there's some other sensors I can look at to help diagnose the issue. Any advice is appreciated, I may have bit off more than I can swallow with this car.



Passed Driver's Ed
Moraga, CA
^ This.

Do you have a stock IC or an aftermarket? I am guessing at stage 2 you have an aftermarket?

Sure sounds like a boost pipe blew off. Others more educated in codes can chime in. But some of those def look related. Especially the misfires.

I would not drive it like this. The turbo may be overworking to try and reach boost but instead blowing it to nowhere. Possibly the whistling you are hearing is the turbo itself. Do you know what tha actual oil temp is?

good luck.



Autocross Champion
MK7 GTI 6sp w/PP
I'm going to say loose I/C charge pipe.


2022 Tesla Model 3
@allenye2008 Ill also say, probably one of the intercooler couplings down by the front of the engine. If one of those partially blew off then you will still get air flow to the engine and it can still be drivable but it will feel underpowerd as hell.