bought the car off my dad a year ago!! great car for me and the family but last week the exhaust started blowing from the cat then whilst on the m1 got over 3,00rpm in third the power died like no turbo could this be down to exhaust or more sinister things??? any help will be much appreciated!!!! also any gas boiler problems you have i may be able to help you scratch mine i'll scratch yours!!

Sounds like it has gone into limp mode, where the turbo stops producing any boost and the car is basically running as a normal diesel with no turbo.

I believe on the TDIs this can be caused by sticking vanes in the turbo, and as it's an SLX I'm guessing it's quite old? If they're not given a good run every now and again the vanes stick.

If you do a search on this part of the forums for "sticking vanes" it should come up with some threads explaining it

If power cycling the ignition when this lack of power occurs then I would agree that car is detecting an overboost (check for fault codes). The normal cause of this is sticky vanes in the turbo, especially brought on if the car is never driven hard. Other faults can be MAF related or n75 valve or maybe coolant sensor, or even a vacuum leak.

If it the car lacks power *all* of the time, then I would suspect maybe the MAF to start with, disconnect the MAFand drive the car, it will run with default values and if it feels more lively then that is the issue. New MAFs are about £50-60, get a proper one, and avoid cheapo ones on ebay.