One problem related to o2 sensor has been reported for the 2003 GMC Yukon. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 GMC Yukon based on all problems reported for the 2003 Yukon.
The contact owns a 2003 GMC Yukon xl 1500. The contact mentioned that the previous owner of the vehicle experienced a failure with the reduced engine power warning indicator. The dealer replaced the throttle body, but the failure continued before the contact owned the vehicle. The contact experienced the warning light randomly flashing, which drastically reduced the speed to less than 20 mph. The contact had to constantly turn off and restart the vehicle, but the failure continued to progress randomly. The dealer replaced the wiring, 02 sensor, the throttle body was replaced a second time, the battery, and the alternator. The repairs failed to provide a permanent solution and the warning light continued to illuminate for the reduced engine power. The vehicle was not repaired. The manufacturer was not notified. The approximate failure mileage was 188,000.