How long should a muffler/exhaust system last? I may be barking up the
wrong tree, but my 95 E320 sounds like it has dropped a couple of octaves
over the past year. I can hear a significant difference in tone between my
99 E320 and the 95. And I have also noticed that highway fuel economy
appears to have dropped from about 25/26 mpg to ~21/22mpg. The car just
passed its emissions inspection, so I'm assuming that the catalytic
converter is still working correctly.