Thanks steve, your a champion. it's good to get confirmation of the possible causes, this issue has had me worried about whether i wasted my time and money on the new injectors i put in that didnt change a thing, lol. they probly needed doing anyway. i have a feeling the cat is clogged so i will remove it this weekend and try cleaning it but if that cant be done i'll have to replace it. i have already cleaned the suction control valve so i'll also clean the M.A.P. sensor while i'm doing the cat just to make sure these parts are ok and see what change occurs. i'll post the result for future users reference. cheers mate.