Inspection Procedures

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

Are DTCs relating to HO2S, fuel system, EVAP system or ignition system set? 

No: Go to next step.

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

1. Check air leakage and connection (especially PCV, PCSV, ISCA hose, throttle body, intake manifold and brake booster).

Is any problem present? 

No: Go to next step.

Yes: Repair or replace it.

1. Disconnect PCSV connector and EVAP hose (PCSV side) between PCSV and canister.
2. Check vacuum at PCSV.

• Refer to  EVAPORATIVE (EVAP) CANISTER PURGE SOLENOID VALVE  . 

Is PCSV normal? 

Yes: Go to next step.

No: Replace it.

1. Start engine with the fuel pump disconnected and wait until stops by itself to release fuel pressure.
2. Attach fuel pressure gauge to fuel delivery pipe.
3. Start engine and check fuel pressure at idle.

• Refer to  FUEL PRESSURE TEST  . 

Is fuel line pressure within specification? 

Yes: Go to next step.

No: Check fuel delivery system.

1. Start engine and check engine RPM decrease when disconnecting each injector connector in sequence.
2. Measure the decreasing engine RPM of all cylinders.

Is there any cylinder with no change in RPM or only a small RPM change? 

No: Go to next step.

Yes: Repair or replace it.

1. Remove spark plugs and inspect spark plug tips.
2. Check abnormal color of spark plug tips compared to other cylinders.

Is any spark plug with abnormal color compared to other cylinders? 

No: Go to next step.

Yes: Check engine for mechanical failure. If it is okay, replace spark plugs.

1. Temporarily install a good HO2S and check for proper operation.

Is problem corrected? 

No: Go to next step.

Yes: Replace it.

1. Check for ECM input signal from MAFS, TPS and ECTS.

Are input signals normal? 

Yes: Proceed with ECM PROBLEM PROCEDURE .

No: Replace all failed parts.