Diagnostic Aids

WARNING: This page is about a different car, the 2002 GMC Sonoma and 2002 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.

An intermittent may be caused by any of the following conditions:

Low system airflow may cause this DTC to set.
Excessive exhaust system back pressure.
Moisture, water, or debris ingested into the AIR pump.
Pinched, kinked, heat damaged, or deteriorated hoses or vacuum lines.
Restrictions in the pump, inlet duct, or filter.
An AIR pump that has become inoperative and showing signs of exhaust gases in the outlet port would indicate a check valve failure.

Thoroughly check any circuitry that is suspected of causing the intermittent complaint.