The latest 2009 Roadster 100 problem was found by the factory to be caused by a slight fuel leak around the Tank Sensor found using a pressure test. Prior to this latest of a series of resettings, the car has done thousands of miles.
Another had an earthing problem from the Fuse Box solved by adding an extra earth cable.
Most others seem to be Lambda or Catalyst related but need to be resolved by getting the ECU back to the factory, preferably on the car.
If you buy a tester it may be worth speaking to Mark Baldwin at the Factory to ask what Code Numbers are likely to be causing the fault as they have dealt with oodles of these and said that dealers should be gathering a list of faulty codes to 'switch off'.
OBD II code reader example - (Maxiscan MS300 less than £20 on Amazon & comes with manual & a list of codes)
