Two problems related to manifold/header/muffler/tail pipe have been reported for the 1998 Plymouth Voyager. The most recently reported issues are listed below.
Vehicle has an exhaust manifold crack.
When accelerator is pushed a buzzing noise occurs. The mechanic at the dealer said it was a warped manifold. He also stated that he'd seen two instances in three years and didn't know what causes it. He stated that it should not be driven in case other systems might be affected.