fzturbo

hi, i have a IHI vf22 and was boosting about 1.6 1.7 bar with no problem for about 5 months, but from one day to another it began knocking at 5500 to 6500 RPM with 1.6 bar. I cleane inyector, changed the MAF, changed the fuel filter, installed a fuel pressure regulator, checked the crank and cam posittion sensors, changed spark plugs and nothing, it's still knocking. i tink it can be a timming problem, not a fuel problem, but the wei thin gis that a few month ago, boosting the same pressure, the car was ok. Can be the Knock Sensor gone bad, or anyother sensor????, please help me, because the problem started suddenly and i'm getting mad with it. If anyone experienced this after, please help me solving the problem.
thanks.

fzturbo

TTT