Check Engine Light Due to Oxygen Sensor Failure on GMC Sonoma

Problem Description and Possible Solution

The oxygen sensor can fail causing Check Engine Light illumination and the engine to run rich (burn more fuel than normal).

Problem Data
RepairPal Verified
Average mileage: 135,886 (111,772–160,000)
Exhaust & Emissions affected: 2.5L 4 Cylinder
5 model years affected: 1991, 1992, 1993, 2000, more2003
6 people reported this problem
Viewing 1 - 2 of 2 comments
oxygen senor bank one melted wire connector dont know how to resplice black and grayon one end and purple and blue on the other
Just purchased this from someone and had it serviced--brakes, oil change, etc. After driving around for about an hour, the Service Enging Soon light comes on. It does not affect the car's running, but the miles per gallon seem extremely low.