One problem related to manifold/header/muffler/tail pipe has been reported for the 2008 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 GMC Sierra 1500 based on all problems reported for the 2008 Sierra 1500.
Broken exhaust manifold bolts. As of today I have a total of (3) bolt heads that are broken. (2) on drivers side and (1) on passenger side. The exhaust fumes are beginning to leak inside of the cab especially when stopped at intersections.