Component Inspection

■ Monitor the Catalyst Converter 

1. Clear DTC.
2. Start the engine and warm it up until the radiator fan comes on (more than at least 10 minutes).
3. Drive at a steady speed between 45-55 mph (72-88 km/h) for 30 seconds.
4. Stop and then maintain idle state for 120 seconds in D-position.
5. Repeat step 3 once again.
6. Stop and then keep it in idle state (D-positon) for 120 seconds.
7. Repeat step 3 once again.
8. Stop and then maintain idle state for 120 seconds in D-position.
9. IG "OFF".
10. Repeat steps 3 through 9 three times.
11. Check if catalyst monitoring readiness is complete. so, if the readiness is incomplete, repeat steps 2 through 10.
12. Does the scan tool show DTC P0420?

    YES 

    • Substitute with a known - good Catalyst Converter and check the signal waveform of HO2S for proper operation. If the problem is corrected, Go to "VERIFICATION OF VEHICLE REPAIR " procedure.

    NO 

    • It was intermittent failure.