VW Golf 7 2015 2.0 TFSI Start Issue & Power Loss

[anass_f]

Hi guys,
I'm a newbie in the automotive diagnostics.

Here are the details of the car:
Golf 7 R 2.0 TFSI 2015. Odometer: 29.000 Km.
VIN: WVWZZZAUZFW020362
Engine ECU: CJXC / 5G0906259E

The problems:
- One DTC as shown in the image below.
- Long cranking before start.
- Loss in power and sudden speed drops.

I can see in the measures values the high pressure value is only 8.8 bars instead of 50 but would it be something other than the high pressure pump. I suspect an other guy here in the workshop has touched something in the engine adaptation values because the car didn't suffer anything related to the engine when the owner brought it to the workshop.

I have done every possible adaptation using the guided function of ODIS and I've seen some adaptation values have been changed then but the problems didn't change at all what ever I change in those adaptation values.

The measurements values in the image below were taken while the engine is running idle. I'm using ODIS 4.0.0.

Please help me pinpoint the culprit of this mess.

DTC.jpgMeasurements.jpg

[shafo]

What did the car come in for originally? Maybe a low pressure pump in tank starting to fail??

In my experience no adaption or coding faults are going to cause low fuel pressure...not sure if the mk7 has a low pressure pump control module..but maybe worth doing basic setting on that

[anass_f]

I don't know how do you call it in English, the car has a modified exhaust pipe that makes explosion sound. The owner was complaining he's hearing some sort of disturbing whistle sound coming from the exhaust pipe.

The guy in the workshop was trying to modify the adaptation channels and reverting back when the change doesn't suppress that whistle sound. Since those adaptation channels were in English he didn't know what channel to suspect which are related to the exhaust system. But he assured me he reverted back every channel he changed.