Danny

the engine loom will allow you to self test without any gizmos. If I remember rightly, by the ecu is a 3 pin connector on the loom - if you put a wire to connect the bottom two outlets together then the red ecu warning light by the clock will flash the code sequence if there are any faults.

The codes are listed in the workshop manual (if you dont have one post up the code and I will check to see what it is). They are not stored by the ecu though therefore if you switch off the ignition the code is lost until the fault occurs again

Hope that helps