One problem related to manifold/header/muffler/tail pipe has been reported for the 2004 Acura MDX. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Acura MDX based on all problems reported for the 2004 MDX.
A loud "droning" sound comes out at 2,000-2,200 mph, especially loud at approximately 40-45 mph. Dealership and manufacturer say that this is a "natural sound" of the 2004 Mdx. I do not buy this explanation it is hard to believe that an expensive SUV such as this would have a "natural sound" like this loud droning sound. It is very loud especially during cold weather. They insist that this is related to the new dual exhaust system of the 2004 Mdx. What if it is engine or transmission related?.