Recently bought a 86 LE with 149K miles on it. The van had been sitting a while so I replaced the air intake tube (was mostly duct tape), air filter, plugs, wires, cap, rotor, fuel filter, and ran some gas treatment through it. Fires up immediately (hot and cold) and runs great in town and on the highway except for the lack of power below 2K RPM's. Runs out great on the highway with no issues. Trans shifts from park to drive slightly rough but it shifts crisp and smooth where expected otherwise.

No check engine lights.

My initial thoughts are a plugged catalytic converter? The exhaust has a pretty strong odor but no visible blue or white. No losing coolant or burning oil.

Appreciate any input.