DTC Confirmation Test

Ensure intake air temperature is 6.8°F (-14°C) or more, vehicle is at an altitude of 8000 feet or below, and barometric pressure is 75 kPa or more. Turn ignition off, connect scan tool and turn ignition on. Using scan tool, clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. Start engine and allow it to reach normal operating temperature. Drive vehicle at speeds of 40 MPH or more for 5 minutes or more. Stop vehicle and allow it to idle for 10 seconds. Using scan tool, check for current or pending DTC P0121. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If DTC resets, go to DIAGNOSIS & REPAIR PROCEDURE  .