OK chaps, here's one for the testbook experts. The engine warning light is permanently lit, and the fault shows as cat/s fubarred. Not surprising,given the amount of playing around I have done with the LPG system. Given that I do not need cats to pass the emission test, can I remove them from the exhaust system, or will this cause an ecu brainstorm, and does this have to be programmed with testbook in order to extinguish the warning light? Answers on a christmascard please........