One problem related to engine exhaust system has been reported for the 2021 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2021 GMC Sierra 1500 based on all problems reported for the 2021 Sierra 1500.
Corroded grounding strap failed cylinder 5 glow plug circuit cracked and separated exhaust backpressure valve.