check for codes and check fuel pressure first and second. I would get it running properly before thinking about mods. The 92-93 dakota/ram had some unique things about them like the big bore exhaust manifolds and its been said the cam and torque convertor were tweaked those years as well.

Some common 5.2/5.9 magnum issues to check:
plenum plate
EGR
spark plug wire routing
wiring splice corrosion under fuse box on 92-95 dakotas

If your exhaust leak is before the oxygen sensor, gotta fix that first. I have a collection of dakota y pipes if you want one. Dual exhaust kinda tight in that chassis