One problem related to manifold/header/muffler/tail pipe has been reported for the 1997 GMC Sierra. The most recently reported issues are listed below.
: the contact stated in August of 2005 while the vehicle was traveling at 45 mph the muffler fell out of the exhaust. The vehicle was taken into a independent repair shop where a dual muffler was installed. The muffler was not a orginal part on the vehicle; it was installed by an indepentent repair shop.