Diagnostic Aids
A Code EO45 will not be caused by a faulty oxygen sensor. Code EO45 indicates a rich exhaust and diagnosis should begin with the following items:
- A silicon contaminated oxygen sensor will cause a steady signal above .55 volts and set Code EO45.
- Fuel Pressure. System will go rich if pressure is too high. The ECM can compensate for some increase. However if it gets too high, a Code EO45 may be set.
- Leaking fuel pressure regulator or leaking fuel injector.
- Canister Purge. Check for fuel saturation. If full of fuel, service purge system.
- MAF Sensor. An output that causes the ECM to sense a higher than normal manifold airflow can cause the system to go rich. Disconnecting the MAF sensor will allow the ECM to set a fixed value for the MAF sensor. Substitute a different MAF sensor if the rich condition is gone while the sensor is disconnected.
- TPS. An intermittent TPS output will cause the system to go rich, due to a false indication of the engine accelerating.