Hi I wonder if anyone can advise on this one.

My 2.2 Dti was in the garage for springs, wishbones discs and brakes last week.   While it was in I asked them to change the engine oil and filter.

I am now suffering from the following problem.   The car souinds a bit roughh when idling and when you rev the engine there is a "piston slap" noise.   When driving the engine doesn't pull like it should and if you rev near 4000rpm the eml comes on and the car goes into limp home mode.

I have read the fault code and P1125(3) Critical Malfunction shows up.

I have cleaned the air flow sensor in case it was that.

Does anyone have anmy ideas - are there any vac pipes near the oil filter that the mechanic could have disturbed when he changed the filter.   The car was running superb before the oil change.