I think I have found the source of most of these problems with the broken exhaust manifold studs and corresponding leaks.
The exhaust hangers on the transmission and frame have failed.
These hangers have simple bonded rubber to metal insulators that break loose on all the Pathfinders I have seen.
When these hangers fail there is extreme pressure on the exhaust manifold studs and they eventually break.
Engine flexing and vibration cause this stress on the studs.
The fix is to fix or replace both hangers. The factory hangers will probably fail again.
I have successfully repaired mine by removing them, clamping and drilling thru the metal hangers and insulator and then putting a carriage bolt thru and backing it with a spring. The sprinng keeps the rubber insulator under pressure and still allows some flex.
This fix has worked on my 1992 for many years and I have had NO problems.
I hope this help more folks avoid these problems.
I would recommend all owners check these hangers.
Sparky
