Hi Olly Thanks for getting back to me I have kinda been chasing the fault but without success so far I serviced the car air filter spark plugs dizzy cap and rotor, to no avail. I replaced the coil pack but it made no difference. The lambda sensor if faulty will it cause over fueling? I have been told if the cam sensor is faulty it will inject fuel 4 time per revolution instead of once is that right?. I figure it is cheaper in the long run to keep changing sensors until fixed but if I new how to test the sensors it would be a help. Regards max