Engine Controls - Trouble Shooting - No Codes - 2.2L: Overview Pontiac Sunfire I

Test Description

The numbers below refer to the step numbers on the diagnostic procedure.

1. 4 - The exhaust system has very low back pressure under normal conditions. If the exhaust system is restricted, a significant increase in the exhaust pressure is noticed on the exhaust back pressure gauge. Removing the HO2S sensor may set a DTC. When finishing this diagnostic procedure, clear all codes using a scan tool.
2. 5 - This step will isolate the catalytic converter from the remainder of the exhaust system.
3. 8 - Confirming that the condition has been fixed is essential. If the symptom still exists and the vehicle has a dual exhaust system, proceed to Step 2) and repeat diagnostic procedure on the opposite exhaust pipe.

See also:
• ON-VEHICLE ADJUSTMENTS - CARS