Circuit/System Testing

WARNING: This page is about a different car, the 2006 Chevrolet Monte Carlo and 2006 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Refer to Heated Oxygen Sensor (HO2S) Resistance Learn Reset Notice .

NOTE: Refer to Three-Way Catalytic Converter Damage Notice .

With the engine in closed loop and at operating temperature, increase the engine speed to 1,500 RPM for 1 minute and then return to stabilized idle. Is the HO2S 2 voltage parameter as active as the HO2S 1 voltage parameter?
- If it is as active then proceed with Circuit/System Testing.
Inspect the catalytic converter for the following conditions:
- Dents
- A severe discoloration caused by excessive temperatures
- Road damage
- An internal rattle caused by damaged catalyst substrate
- Restrictions
- If a condition is found, then replace the catalytic converter.
Inspect the exhaust system for the following conditions:
- Leaks
- Physical damage
- Loose or missing hardware
- Properly torqued HO2S
- If a condition is found, then replace the exhaust system.
Inspect the HO2S 2 for the following conditions:
- Grounded wiring harness
- Damage
- If a condition is found then replace the HO2S 2.
- If no physical condition is detected and the HO2S 2 is as active as the HO2S 1 after operating the engine at 1,500 RPM for 1 minute and then returning to a stabilized idle, then replace the catalytic converter.