Check intake and MAFS for source of any air leaks.

Check any cracks or deformation on MAFS and check that MAFS is installed in correct position.

Verify oil cap and dipstick are properly installed and oil cap screwed on completely.

Has a problem been found?

YES

▶ Repair or Replace as necessary and go to "Verification of Vehicle Repair" procedure .

NO

▶ Go to "APS Inspection" procedure.

Ignition OFF.

Connect Scantool and monitor Accel Position Sensor parameters on Current Data.

Specification : Approx. 0.4 ~ 0.7V(at Idle), 4.4 ~ 4.8V(Wide Open Throttle)

Is parameter displayed within specifications ?

YES

▶ Go to "Check EGR solenoid valve operation" as below

NO

▶ Go to "APS Inspection" procedure. For more detail inspection, refer to DTC P0120,P0123, 0220,P0223 and P2123 for APS troubleshooting guide.

Ignition "ON" & Engine "ON".

Confirm that EGR solenoid valve Duty is 5% after warming-up Engine.

Be sure that vacuum is felt after disconnecting vaccum hose from EGR solenoid valve.

Check that vacuum is felt in idle after sudden accelleration(EGR solenoid valve Duty : 95%)

Is the vaccum felt from vaccum hose according to EGR DUTY ?

YES

▶ Go to "W/Harness Inspection" procedure.

NO

▶ Check EGR solenoid for contamination, deterioration, or damage. Substitute with a known-good GR and check for proper operation. If the problem is corrected, replace EGR and then go to "Verification of Vehicle Repair" procedure.