92 lumina with a hesitation problem

We have replaced trans,changed tps,iac,o2, map,crankshaft sensors, removed converter,did a tune-up,replaced ignition module and all three coil packs,and replaced the brain.If anyone has a clue I sure would appreciate a fresh thought on this old problem

Put the catalytic converter back on, and check for vacuum leaks and proper routing of all vacuum hoses.

After removing converter and replacing crankshaft sensor vehicle ran for 6 months. Problem came back we cleaned crankshaft sensor, vehicle ran fine for 15 minutes and then started hesitating to the point of not starting. Now it will start and has a miss. Don’t know what the problem is.
I don’t want to drive it again for 15 minutes to be stranded again.

I had significant hesitation and stalling when stopped on a 91 lumina 4dr. Finally solved by replacing plugs and wires. This car seems to be a bit hard on wires – it likes a new set every 20k miles or so.