Two problems related to manifold/header/muffler/tail pipe have been reported for the 2004 Chevrolet Silverado. The most recently reported issues are listed below.
Exhaust manifold bolt on driver side at rearmost part of engine has broken off.
I went out to leave for a meeting and started my truck. I heard a ticking noise that I had not heard prior to this morning. I opened the hood to investigate the cause of the ticking and discovered on the left bank one of the exhaust manifold bolts was missing the head. I then went around to the right bank and noticed that the exhaust manifold was broken completely about mid way of the manifold. I have owned this vehicle since it was new off the dealership and have had very little issue with it until this issue popped up. I have done some research and discovered that this is a major problem affecting Chevrolet and gm vehicles with 8 cylinder engines. This vehicle is used as a daily driver and is not used for commercial towing, nor is it used for towing on a regular basis.