Two problems related to manifold/header/muffler/tail pipe have been reported for the 2004 Toyota 4Runner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota 4Runner based on all problems reported for the 2004 4Runner.
Frame has way too much rust for a vehicle of this age. Exhaust manifold ticking noise. Both are well documented issues with this model year. . . .
When driving my 2004 Toyota 4 runner emits a sulfur like odor. I have been told that switching fuels will help, but I have tried all fuels in the area of all grades and still have this terrible smell. It happens on a repeatable basis, most of the time after exiting the freeway onto a surface street is when it is most noticeable.