Vauxhall Astra 17 Diesel Limp Mode

Vauxhall insignia cdti engine light on and limp mode.
Vauxhall astra 17 diesel limp mode. Astra mk5 17 dti estate 2005 i have just come back from a 150mile tripwhilst on the motorway the engine management light will come on and the car goes into limp mode then a few miles later the light goes out and everything returns to normal for a while. It would sometimes enter limp mode mid journey then behave normally 30 minutes later. Hidden and not so hidden features of the vauxhall astra hmk5. P1625 c main relay stuck open.
P0400 4 egr voltage low. Vauxhall astra 17 cdti revs to 30 then goes into limp mode drives fine then looses power no acceleration goes into limp mode turn engine off for a few minuets and it drives for a few yards and does the same again it only revs to 30. The topic problem with vauxhall 17 ctdi diesel is closed to new. This isnt what my astra did.
Hi everyone my brother had just bought himself a astra 17 cdti he was driving at 70mph yesterday and the car went into limp mode and will now not start it did start day after but died again after a few seconds ive done pedal test for him and were getting code p0002 any advice please. How to clean maf sensor astra j 17 cdti 81kw.