One problem related to engine exhaust system has been reported for the 2011 GMC Terrain. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2011 GMC Terrain based on all problems reported for the 2011 Terrain.
Significant exhaust fumes accumulating inside passenger cabin during idle/stop. Volume of gases smell less while in motion but still evident. Significant reduction in engine power noticable; as well as erratic noise from the engine and extemely hesitant acceleration response.