Every now and then when it's sitting at idle, or on brakes, my jeep will start running really rough. Doesn't seem like it's the IAC because the rpms jump up and down pretty quickly. Recently replaced fuel pump due to drain back, but I checked the fuel pressure and it held around 50 psi no problem. Cleaned IAC and throttle body, replaced cap / rotor and cam sensor after it stalled while driving and gave me the cam position code. That was the first time it threw a code after about 2 months of the occasional rough idle, but after replacing the rough idle still persists. Should I be looking more into ground wires? Possible ECM swap, EGR valve? I wouldn't think it's O2 sensors due to no codes. Also, it's a 97 XJ with no mods to the engine. Valve train looked immaculate when I recently changed head gasket. 250k+ on engine but normally runs excellent.