Engine light on - code means turbo boost pressure high. help!!
I have a 2005 GT 1.9JTD. Had it 2 days and the engine light came on and it went into limp mode for a minute or two. Diagnostics show turbo boost pressure high, and the garage said it's recently had a new map sensor so it could be the turbo pressure sensor or ecu, although a common fault is the egr valve.
The mechanic went for an egr fault and fitted a blanking plate with a hole to let some gas through so as to avoid it causing the engine light to come back on. This has improved idling which was sometimes lumpy, and improved some hesitancy in acceleration changing from second to third in particular.
However, when out for a spin at the weekend the engine light came back on and the car went into limp mode. The mechanic now says it could be the turbo fins sticking, and has suggested 'washing' them by pouring some cleaner in somewhere and leaving it for a few hours. Recons on it costing £50.
Just prior to the light coming on, I was on both occasions gently accelerating in 5th gear and on the second occasion I felt there was some hesitancy again in the lower gears 5 or so minutes before the light came on.
Given that the mechanic has suggested 4 causes and addressed one which hasn't rectified the fault, I would appreciate any ideas, rather than throw money at one failed attempt after another.