hello

vag com give me this code - 17656 - Start of Injection Timing Regulation: Control Deviation

recently i had a bump on the front of the car, after that the intercooler was cracked, i repaired that all was fine

now when i pulled in the other day and started it up again it sounded like a bag of hammers, it was extremely violent to start and the turbo just wont boost before 2.5k revs then after it boosts 100% (still rought though)

any ideas where i can start?

my car is Bora Sport 1.9 AHF 110PS