H81 - Check For KOER DTCs 1137, 1138, 1157, or 1158

- Key Off.

- Scan Tool connected.

- Key On, engine idling and stabilized.

- Activate KOER self test.

- Check for DTCs.

- Are DTCs 1137, 1138, 1157 and 1158 present?

YES -- Go to H83. H83 - Check Exhaust System For Leaks

NO -- For codes 0136, 0156: Go to H82. H82 - Check For Crossed HO2S Harness Connector

For DTCs 1137, 1138, 1157 and 1158: The fault that produced the DTC is an intermittent. Go to Pinpoint Test Step Z1 with the following data: HO2S-11, 21, 12, 22 PIDs and list of possible causes. Z1 - Intermittent Test Procedure