I started my motor one morning. It sounded like an exhaust manifold leak so I took it into my mechanic. He did an diagnosis on the truck and found that 2 of the exhaust manifold bolts were broken on the passenger side exhaust manifold. He took off the manifold and found it to be warped. He also found that the exhaust manifold on the drivers side was also warped. He removed both manifolds and removed the bolts. He replaced the manifolds and the truck runs great. I notice a big difference in performance. I think there was a problem for awhile but there wasn't any noise coming from the exhaust manifolds. Cost of this repair was $900. Has anyone had this problem?