I've got 2009 2.0L diesel which kept cutting out when idling, it's had a regen and the egr was tested and found to be ok, I was told it could only be the air mass sensor which I replaced it doesn't cut out anymore but there is a lack of power which suddenly cuts in like really bad turbo lag, could it be something else or a dodgy sensor which I bought online?

 

My only experience with diesels is with large freight liners/international medium duty chassis at work. No idea if this is applicable for you at all. Our mechanic is very not impressed with manufacturer regen systems because they generally manage to clear off just enough of the exhaust filter to clear the regen code, but doesn’t actually clear the whole filter. He describes it as using an air hose to clear off a dirty screen might clear enough to see through, but doesn’t clean the whole screen.

he much prefers we do driving regens on the highway, steady throttle speed going around 50-60mph for about 20-30 min. Last time around he did a drive with me with his maintenance computer plugged in the whole time to track all of the parameters, and the exhaust temp readings. When we started we had something like 200 degree temp differences between the manifold and post filter. It really did take a long time to burn all of the junk off, but when we were done it had pretty balanced temps and cleared all of the codes.