Test Description
WARNING: This page is about a different car, the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, and 2002 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers in the diagnostic procedure.
- 4
An HO2S contaminated by silicone will have a White, powdery deposit on the portion of the HO2S that is exposed to the exhaust stream. The usual cause of silica contamination is the use of unapproved silicone RTV engine gasket material or the use of silicone based sprays or fluids within the engine. If the cause of this contamination is not corrected, the replacement HO2S will also get contaminated.Perform the DTC P1441 diagnosis to determine if an EVAP purge condition is present. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
- 8
When testing the circuits for continuity the resistance should be less than 5 ohms. When testing the circuits for shorts the resistance should measure infinite with all components disconnected from the circuit. - 9
This step determines if a base engine concern is causing the rich condition or if the rich condition is only present when operating on CNG. - 10
An HO2S contaminated by silicone will have a White, powdery deposit on the portion of the HO2S that is exposed to the exhaust stream. The usual cause of silica contamination is the use of unapproved silicone RTV engine gasket material or the use of silicone based sprays or fluids within the engine. If the cause of this contamination is not corrected, the replacement HO2S will also get contaminated.