Originally Posted by mechanic28

mine used to smoke quite heavy on the over run (fuel)since i had it mapped by karl it has been cut to next to nothing,but still does puff abit!karl told me that the problem is within my L6 ecu even tho the tps switch is telling the ecu that the throttle closed and the engine is on over run the ecu is still telling the injectors to inject and not shut off!he managed to map it so they are injecting next to no fuel so smoke has been reduced lots!he said this is a problem he has only seen on L6 and not on the L8