Hello, I have a Mk2 Superb 2.0TDI 170bhp CFGB engine and have covered 160,000 miles. The car has been properly maintained and serviced throughout at fixed intervals.

In June 2025 at 157,000 miles the EGR was replaced by a VAG specialist and a mod to the pipe work was made. SInce then the car has twice gone into a limp mode with (according to CARLY) fault code P040300 - Exhaust Gas Recirculation Circuit.

I plan to send the car back to the specialist but it has occurred to me that the EGR circuit pipework may be coked up along with the inlet manifold. With that in mind I looked at companies who clean the EGR circuit and DPF.

One of them has suggested that they not only clean the pipework but re-map the ECU to permanently close the EGR valve bypassing the engine. Does anyone have experience of this? It seems like an attractive option but want to make sure there aren;tr an downsides I should be aware of. Cost is apparently £390.

Moderators I wasn't sure where to post this as the CFGB engine has been used in many Skoda models so please feel free to move if there is a more appropriate section.

There’s a pipe that comes from the cylinder head to the inlet manifold.

There’s a part held in to the inlet with two screws

I’ve removed that in the past and it’s been built up

May be worth a check