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.

Possible Causes

Possible Causes
RESTRICTED INTAKE AIR FLOW (PLUGGED AIR FILTER)
LEAK IN THE EXHAUST SYSTEM
UPSTREAM AND DOWNSTREAM O2 SENSOR HARNESS CONNECTORS SWITCHED
O2 SENSOR 1/2 INSTALLED INCORRECTLY
O2 SENSOR 1/2
ENGINE MECHANICAL ISSUE CAUSING O2 SENSOR CONTAMINATION
POWERTRAIN CONTROL MODULE (PCM)

Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .