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 procedures.

4

The engine may also have a higher than normal idle if a vacuum leak is present.
An exhaust system leak may be very small and cause the oxygen sensor to sense a false lean condition.

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 lean condition or if the lean condition is only present when operating on CNG.