Note. Before performing any diagnostic test, refer toWARNINGS, CAUTIONS and NOTES in DIAGNOSTIC TESTS .
Note. Testing individual components does not isolate shorts or opens. Perform all voltage tests using a Digital Volt-Ohmmeter Meter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.
Diagnostic Aids
Engine/Transaxle Control Module (E/TCM) or Engine Control Module (ECM). monitors HO2S once per trip and will set a code when air-fuel ratio is forcibly changed (lean to rich to lean), HO2S signal does not provide response within 1.28 seconds. Check for following possible problems
- Abnormal combustion.
- Improper fuel pressure.
- Front and rear HO2S connections reversed.
- Fault in fuel delivery system.
- Leak in take system.
- Leak in exhaust system.
- Faulty front HO2S.