With GST

1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Calculate the total value of "Short-term fuel trim" and "Long-term fuel trim" indications.

   Check that the total percentage should be within ± 15%.

   If OK, GO TO the following step.

   If NG, check the following.

   • Intake air leaks
   • Exhaust gas leaks
   • Incorrect fuel pressure
   • Lack of fuel
   • Fuel injector
   • Incorrect PCV hose connection
   • PCV valve
   • Mass air flow sensor
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3, 500 and 4, 000 RPM for at least 1minute under no load.
6. Let engine idle for 1 minute.
7. Increase the engine speed up to between 4, 000 to 5, 000 RPM and maintain that speed for 10 seconds.
8. Fully release accelerator pedal and then let engine idle for approximately 1 minute.
9. Select Service $07 with GST.

If 1st trip DTC is detected, GO TO "DIAGNOSIS PROCEDURE ".