The design of the manifold sucks. The heat from that side of the engine heat soaks the injectors and it will run rough. Typically you will get misfire codes with that. There are ways around it. I bought new injectors and wrapped them with heat shield tape. There are also heat shields available to help block the problem areas.
1996 Jeep Cherokee- Project-- Rusty's 8in long arm, SYE kit, Teraflex driveshaft, Cragar soft 8's 15x10 with 33x12.5 Firestone Destination MT's, Eaton Tru Trac in the front