Tune with inlet pipe replacment?

[ants87ss]

I have a '08 MS3 I just replaced the head gasket on. Stock inlet pipe broke so I replaced with JBR pipe and intake hose, but kept stock airbox. The car breaks up on light throttle at low rpms. I have checked for vaccuum and boost leaks and found none. I have no codes. Would I require a tune even though I kept stock airbox? I am using the free version of VT to log and get data to try and diagnose the issue. I notice that my STFT gets in the 20s while driving, which would indicate a vacuum leak, but as I said I have checked everything. Thanks in advance

[mituc]

Nope, no tune changes required for what you did on the car to fix it.
If the STFTs get to 20 then most likely you have a vacuum leak as you suspect.
Please download this dashboard preset and take a log with the car breaking up, post the log here and let's look:
https://www.dropbox.com/scl/fi/55qyxbqs ... khuf9&dl=0

[ants87ss]

Here's a log from a third gear roll on

[mituc]

You need to service/replace your HPFP (or the internals). ASAP, because they are damaged or the pump is clogged.
Also, the boost control system is not working on your car, one of the lines going from the turbo compressor housing to the wastegate actuator or from the wastegate actuator to the EBCS (or both) is disconnected or cracked (or chocked if it's the one from the compressor housing to the wastegate actuator).

Also your engine coolant temps readings are very weird, the temps is raising very fast, probably because the engine is now a flame thrower with this fueling issue going on, or maybe you have a stuck semi-closed thermostat (or was replaced with an incorrect unit).

And by the looks of it your car may also require servicing of the timing parts.

So yeah, it doesn't look good at all...

[ants87ss]

Thanks Mituc. Yes, I noticed the engine temp rising quickly as well. I replaced all timing components when I replaced the head gasket except the variable timing actuator on the intake cam. I will service the hpfp and take a look at the hoses going to the wastegate and solenoid as well, and report back. Thanks a ton and I appreciate your feedback