Stalling and backfiring

Yes completly rebuilt the intake lower and upper theres no vacume leaks at all. I checjed the timing chain also its fine. Ran a compression test its fine. And I litterally took the wiring harness aparts cleaned up any questionable wiring and cleaned out all plugs and what they plug into including the ECM.

Its definatly electrical whatever it is. It runs like a top until it gets good and warm then it happens. Almost act like its got a clogged converter acts when it happens. Yesterday drive 30 miles fine. Shut it off walked in the house. 3 minutes later try to leave backs out fine takes of then starts studering like its missing. Take it back let it sit 3 hours then drove 30 miles more without an issue.

Yes besides cleaning the prongs and connections with sensor cleaner I did remove the motherboard from the plastic sleeve. I thoroughly checked all the tiny circuits for scorch marks breaks or cracks both sides. I did this because the dash lights have been acting funny. 2 days ago i started it and it said the abs and brake light was on checked the brake it was not engaged. And the abs is not possible as i just replaced both front hub assemblys with abs and i cleaned those connections 6 days ago. When i shut it off and turned it back on immediatly the lights were gone. A few days befor that it started and had the air bag light on and i didnt even know it had that light on the dash at the same time the gas gauge would go to the current fuel amount in the tank then drop to E then go back to the acurate level about 4 times. At the same time the dash backlights were coming off and going on at the same rate as the gas guage but i was early noon sunny day no reason for the backlights to even engage. Same thing though turned the car off then back on none of those things happened again

Ok thanks alot for everything. I will figure out were the bcm is located then i will check it out and let you know what i find

Ok so niw im confused I aparently cleaned and investigated the bcm not ecm ha ha. So the bcm is visibly good now i gota find the ecm.

Ok so new symptom. I noticed the serpintine belt was badly streched so i replaced it. But my problems still there. But i noticed the cars trying to cut off and keeps poping the battery light on then off immediatly! When it completly breaks down with the jerking or sputtering like a bad miss and completly dies and wont start. Today i noticed the altinators super hit and im getting a burning or hot plastic smell pretty pungent. It still wouldnt start i touched and held the egsaughst manifold after sitting 40 minutes. It was warm still as expected afyer 25 miles. But the alternator was still raging hot. Like i couldn't hold my hand on it at all!. But i took it off and autozone test it and it passed twice. Im thinking maybe its shirting out and overheating then throwing off the current to everything else or something. What does anyone else think about that theory?

Nope not the altinator neither lol! Its not getting hot like the other but my oroblem remains.

My 97 park avenue does the exact same thing..my mechanic friend thinks its tge manifold gasket. .ive replace map and maf sensor and it still throws a code for the map sensor..its super frustrating because some days it runs completely fine! If you figure it out please post wtf you replaced lol and i will do the same.

Why is it cutting out when everything is new