95 sc lost power and wont run right

I was driving down the Interstate lost all power, and the engine died. After a few mins. it started back up but i could only drive in 1st or 2nd gear in an automatic or the engine would die. The headers got red hot while the car was running and melted everything in the converters. We hollowed them out and it still didnt run right. switched out the maf sensor and fuel pump and fuel filter and still has no power. Does anybody have any ideas what could be wrong??

and the engine was replaced 20k miles ago.

it will not run right because now your o2 sensors are not reading right because u have no cats

with the headers glowing and the cats melted it sounds suspiciously like youve got a stuck valve, or one hell of a lean mixture. id pop the valve covers off and assess, go from there. also check the fuel pressure at the rails

Your dpfe is probably telling the egr to stay open and superheating the convertors. If you unplug the O2's the computer will read a neutral signal and start if that's your problem. It could also be a bad MAF messing with your fuel mixture.

i already had the maf sensor replaced and it didnt do anything.