One problem related to rear air suspension springs has been reported for the 2002 GMC Envoy. The most recently reported issues are listed below.
2002 GMC Envoy engine stalls while stopped at traffic light. Sometimes a near-stall condition occurs whereby the engine idle dips really low, engine shudders, then idle recovers. This usually happens just before or after the air compressor for the rear suspension inflates. So far the pcm, throttle body, and ignition switch have been replaced. Dealer is currently making 4th attempt to fix problem. Problem has been occurring since 8/2002.