my 2wd saph has been off the road for about 18 months after some little c**t knicking it and getting about 200 yards before hitting a lamp post. whilst it was off the road i changed the cambelt, new alloy rad, rs 500 cooler and new boost hoses but it will only now hold about 7psi. the car is stage 3 with a bayjoo chip. any suggestions why would be much appreciated. cheers, ben