CASS SC4

same problem...check your sub O2 sensor circuits...not just the sensor its self...check for a fray in the connection or opens in wires before and after the actual sensor...any mods done? also check mass air flow sensor and engine coolant temp sensor...all of these things will cause a rich running condition and even lean at times too...i found out first hand on my 1993 sc400...swapped out stock air intake for INJEN short ram...ruined everything..