Hi all,
I’m trying to diagnose a fault with my Caddy 2K.
At up to about 1800rpm, acceleration under load is sluggish and the engine has quite a loud laboured sound. Along with this, is the occasional smell of diesel like unburnt fuel and the mpg figures are not what they should be.

2008 Caddy with 1.9 BLS engine.
Camshaft sensor implausible signal fault

The camshaft sensor has been replaced twice now, fault condition has improved with the latest sensor, but the G40 fault will not clear. The torsion values have improved dramatically since the last sensor replacement and I made a small adjustment to the cam timing using VCDS as a reference.

I have still to fully check the cam sensor wiring to the ECU, but I have physically checked the wiring down to the starter area, no faults found.

I have replaced the fuel filter, which was as black as the ace of spades.

Being a Caddy, the car is loud inside and it’s difficult to hear the turbo, but low boost might be an issue.

I’d like to know if there are any usual suspects, other than the cam sensor and as far as the sensor goes, what is the best source of reliably functional replacements, as the aftermarket ones leave me in some doubt.

Could someone also please point me in the direction for the measuring blocks to view and the figures that I should be seeing?