Several months ago I noticed the exhaust system on my 97 qx4 sounded like it had an exhaust leak. Further checking showed a cracked exhaust manifold. I figured that would be a very expensive fix by the dealer so I tried various methods of "patching" the crack, none of which worked. One day I was looking through the list of service bulletins on the NHSTA website and noticed a bulletin about extended exhaust system warranties for 97 pathfinders (which have the same engine as the qx4). I found out that the exhaust manifold on both vehicles is warrantied for 100 months or 100,000 miles. So infinity will replace the exhaust manifold free of charge. Just thought I would pass this along.