Thanks very much for the replies and i understand how to build a tester from the diagram from the link provided many thanks. If i may i would like to pick your brains one more time, the misfire only occurs under load IE it wont do it when you free rev it only under load being driven. so do i plug in the LCD before or after the light comes on. What i mean is do i drive it the light comes on i plug in the wire and it will provide the code.
cheers