2004 Nissan Xterra- Exhaust pipe rattle fix.
Don't know if this is a common prolems with the 04 Xterra or not, but I will explain what it is and how I fixed it.
Problem- After we had our 04 Xterra for about 2 months, it developed a strange rattle sound whenever you accelerated. At first it only happened when the engine was cold and it would go away after it warmed up. But after a week or so it was rattling anytime you accelerated regardless of whether or not the engine was cold or hot.
First attempt to fix- I took it back to the Nissan dealership and they told me that one of the catalytic convertors had came apart inside and was causing the rattle. They put a new on it. The rattle stopped for about a day and then returned.
Second attempt to fix-I took it back to Nissan a few weeks later and this time they said that the U-bracket on the Y-pipe on the exhaust, right where it goes into the muffler, was loose. They tightened it and it went away for about a week. Finally I decided to crawl under there and investigate. Sure enough the U-bracket clamp on the Y-pipe at the muffler was loose and you could actually move the pipe with your hands and hear it clang inside of the muffler pipe.
Third attempt to fix- At first I took a 15mm socket wrench and tightened the clamp, this would fix it for about a week and it would loosen up again. Believe me, I was tightening the nuts on the bracket as tight as they would go but somehow they would loosen back up. Nissan put the nuts to the clamp on the upper side of the exhaust pipe so you have to manuvere your arms and hands around and up to be able to get a socket on them and you have to use a shallow socket because there isn't much clearance between the nut and the heat sheild on the bottom of the Xterra.
Fourth and final fix- Finally I went to Advance Auto Parts and bought a
Perfection 517214, 2-1/4" HD Muffler clamp. It cost $2.28 plus tax. I put the new clamp around the pipe right beside the factory one and tightened it up. You could see the two pipes come together tightly and it hasn't rattled since.
Conclusion- If you have an Xterra and are getting some strange rattling sounds from underneath...check out the U-bracket clamp between the Y-pipe and the muffler!