1998 Dodge Caravan Rough idle and stalling

Replaced the engine with a used engine. (3.0L) It started right up, but it was rough and would die within seconds. Replaced distributor cap, rotor, wires, plugs, timing belt and waterpump. Rechecked everything numerous times to ensure nothing was off. Swapped each sensor with known good ones to to rule them out. No check engine light, but still it will not idle and it runs like it is misfiring. Compression is approximtely 150psi on each cylinder, and plugs look like they're burning good. Also noticed catalytic converter is glowing at end, so I disconnected it to see if it might be contributing to the issue. Runs just as poorly with it unbolted. Any suggestions?