Two problems related to engine exhaust system have been reported for the 1999 GMC Sierra. The most recently reported issues are listed below.
Fuel pump will over heat and than short out. Exhaust always rattles engine knocks cat. Converters went out digital display stopped working.
Has occuring ehaust leak, service wont fix. Using brakes while slowing and hitting bump in road, brakes will pulseate very hard and vechile will not stop.