C5 II 1.6 HDi Exhaust system defect

[Dav03k]

For those of you wondering how the other sensors started working: None of them were short circuiting.. I learned that only after putting the new EGR in.

Turns out, my engine really was running too hot because the wastegate actuator minimum setting on my turbocharger was wrong. That needs to be tuned until the engine runs smoothly and when taken on a drive the turbocharger should not make any wierd "sutututu" sounds.

The turbo pressure sensor was alright too. The wastegate actuator was a bit dirty, thus sticky, which meant, that there was too much boost pressure present when it was not needed. I just sprayed some WD40 between the rod that is coming out of the actuator cylinder, moved it around a few times until it moved more easily. That solved it.

Regeneration request too frequent -> disappeared after the EGR was replaced and initialised.

[Dav03k]

I might have to correct some things here...
If your turbocharger breaks down and you choose the cheap option to only replace the core of it, you should then go ahead and let a professional calibrate the VNT actuator arm and the limiter screw on a flow bench. If you do it like I did and just adjust things by guessing, you will never be able to use your turbocharger optimally. This is why occasianally my engine still runs hotter than it should and I feel like it does not have as much power as normal at low rpms. I have already picked up another turbocharger which has been, as far as I know, professionally calibrated.

After fitting I might share my results.

[Dav03k]

The old dog walks again! I have fitted the other turbocharger and the results are clearly better. Turbolag is almost non exsistant and the car has much more power on the lower end.

I also replaced the intake manifold to be free of the gunk that has built up in there due to the EGR.

I might even dare to say that everything is working as it should now.

Thanks for everybody's help along the way. I really appreciated your help.