Diagnostic Aids

Code 45 or rich exhaust is mostly caused by improper fuel pressure, HEI shielding, canister purge, MAP sensor, TPS, O2 sensor contamination, or EGR system. To diagnose components, refer to I - SYS/COMP TESTS article in this section.

If code is intermittent, see TESTS W/O CODES article in this section.

Fig 1: Code 45 Schematic (Except GSi), Non-Heated O2 Sensor Ckt. Rich Exhaust Indicated

Fig 2: Code 45 Flow Chart (Except GSi), Non-Heated O2 Sensor Ckt. Rich Exhaust Indicated