Inspection Procedures

1. Connect Hi-Scan (Pro) to data link connector.
2. Turn ignition switch to ON and monitor other DTCs.

Are any other DTCs also set? 

No: Go to next step.

Yes: Do all repairs associated with those codes before proceeding with this procedure.

1. Thoroughly check connectors for loose, poor connection, bent, corrosion, contamination, deterioration or damage.

Are all connectors good? 

Yes: Go to next step.

No: Repair or replace HO2S.

1. Check exhaust system for leakage.

Is any leakage present? 

No: Go to next step.

Yes: Repair exhaust system for leakage.

1. Visually check intake system for leakage.

Is any leakage present? 

No: Go to next step.

Yes: Repair intake system for leakage.

1. Reduce the fuel pressure to install the fuel pressure gauge.
2. After installing tightly the fuel pressure gauge to fuel delivery pipe, start the engine and let it idle.
3. Check fuel line pressure.

• Refer to  FUEL PRESSURE TEST   of Fuel System for more information. 

Is fuel line pressure normal? 

Yes: Go to next step.

No: Repair it.

1. Reconnect HO2S and ECM connectors.
2. Warm up engine to normal operating temperature.
3. Using Hi-Scan (Pro), monitor HO2S signal waveform.

• Refer to  SIGNAL WAVEFORM   for more information. 

Is the rear HO2S signal normal? 

Yes: Proceed with ECM PROBLEM PROCEDURE .

No: Replace HO2S.