October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.

Code Enable Criteria

Engine speed is 1500-3000 RPM.
Loop status is closed.
Calculated airflow is greater than 7 grams per second.
No CAM, CKP, ECT, EGR, EVAP purge solenoid, fuel trim, IAT, MAP, misfire, O2S1 or TP sensor DTCs are set.

DTC sets if ratio of O2S1 lean-to-rich average time to rich-to-lean average time is not 0.6-2.8 within a 100 second test.