Most likely the passenger side exhaust manifold. The weld at the factory collector is known to break due to the ac draining on it.
Easiest fix is to pick up a pair of 94-98 manifolds
"I'm not driving too fast...just flying too low"
-03 SB Cobra vert- 2552 of 5082 Born 02/25/03
90 7up vert - new project-07 DSG Focus -DD