TPS An intermittent TPS output will cause the system to go rich, due to a false indication of engine acceleration. Code 45, Rich Exhaust Indication Flow Chart & Schematic. Scheme 77 Log in Scheme 77: Code 45, Rich Exhaust Indication Flow Chart & Schematic Code 45, Rich Exhaust Indication. Scheme 78 Log in Scheme 78: Code 45, Rich Exhaust Indication