P0299 Under boost codes Is38

[Andrewbens]

Today my friend brought over his 2017 Dsg Gti with a stage 2 tune from sneeky and the car runs great we installed new motor mounts from bfi and it’s super smooth, but I wanna get to a point the car has never ran strong with his is38 stage 2 setup the car was apr stage 2+ is38 when he bought the car and the tune was weak he went sneeky and it was still weak but much better. I found out the wastegate was only 3.1 volts and had it adjusted and adapted to 3.65 now and the car still doesn’t make the correct amount of boost it’s about 5 psi down.

Here’s my suspect for the code
* Bad DV? Does the latest DV revisions go bad on the mk7?

*faulty map sensor on boost pipe. maybe?

*boost leaks? I’ve checked everything I cannot find any leaks and the car is quiet when mashing the pedal at 100% no weird noises.

*bad turbo? But i would hear a dentist drill noise or something funky and the turbo sounds fine at start up or when you at 100% throttle.

Here’s my link to 2 logs on 2 different maps Datazap

Hopefully this log helps
https://datazap.me/u/andrew149/5150-and-sneeky-log?log=0&data=8-15

Engine Performance mods
-is38
-3” Dp
-ecs fmic
-ie intake with ie inlet
-cts exhaust
-tmd


And here’s a pic of the motor while we were putting in the bfi motor mounts

 

[Diggs24]

Why does a GTI have errors for exhaust flap valves?

 

[Andrewbens]

Why does a GTI have errors for exhaust flap valves?

No idea have you ever seen that?

 

[Diggs24]

yes

 

[Andrewbens]

yes

I’ve looked up the code and could not fine a fix for it.

 

[ryansonfire]

typically an underboost fault for vw/audi would mean the wastegate is loose or there is a boost leak. i would check the play on the wastegate itself back and forth, in and out. it should be tight with almost no play. second i would check that cheap intercooler, ive seen a few with a small pin hole that caused that fault. it could be a bad weld or a loose clamp

 

[Andrewbens]

Update:

Replaced Dv because he had another one in the garage and it did not fix the issue he has turbo discharge pipes in the garage also ready to be installed.I did find one of these pipes cracked where the mounting point was on the side of the motor but I could not confirm if this resulted in a crack pipe or not without removing it.

Also he ordered the apr adapter to test for boost leaks with the regulator. So that will be in soon.

 

[Andrewbens]

Was able to find the issue yesterday the hot side turbo pipe had a crack in it from a accident in the past.

We replaced the part with a used neuspeed hot side turbo pipe

 

[Andrewbens]

Pics