Just had an emmissions test done on our car. The garage said the engine is running very rich and the CO and hydro-carbon readings are off the scale The engine is OBD2 B16a2 being ran by a JDM P30 OBD1 ecu. All works fine (at least that what we thought!) Does anyone know what we can do to lower the fuel mixture i.e fitting a fuel regulator?? I was told that a very rich running engine can seriously damage the lower piston rings, is that true???