Hi
I use Palmer Performance OBD2 scanner which uses Blue tooth connection to the laptop to log and graph results. You can do drag dyno tests with this and if used as a comparison before and after repairs it's very good but I have doubts it will give reliable Torque or BHP results as in a road dynamometer. This one of the best for price and application I could find. Bear in mind it can only monitor mandated info that the US of A use for Climate control. If you want to be more techie go for an Oscilloscope pack from Pico but this won't do interrogation of ECUs etc. or scan the whole lot as you drive along. Manufacturers only allow the minimum data through by law but it does do most of the running checks MAFF, MAP,Throttle pot, fuel flow, rpm, temperature, knock sensor, and the really useful Lambda. Of course if you want to do the whole thing, Maverick Technology do the bees knees with ECU and other interface interrogation for £4000.
Thanks for the reply .
In desperation today i put my "Gendan Engine check" into the OBD socket and hey presto it works
supposed to be fore post 2001 but it works so i aint knocking it