Engine problems after a wreck.
 

I was hit on the right side, causing about 9-10k in damages when counting my body kit,wheels etc.
engine acted funny as soon as i was hit. making weird noises and sounding really weak.

my AT normally idles at 700-900rpm, now when i turn it on it always shoots up to 2000 and starts seriously being weird.

im guessing something is screwed up and dont know what. my insurance company said they will deal with it as it comes and want me to have the body shop look into it but any body shop around here will have no idea wtf they are doing with my engine, correct?? so i have no idea how to get repair cost for whats wrong with my engine now or even where to get it fixed.

should i just reflash the ecu to stock, throw the cat on there and take it to a mazda dealership? idfk >_<; i wish they would just total the stupid thing

mainly just if they want to fix the damn thing after a wreck, i want them to do it right...i dont want to have engine problems in a month and them say not our fault etc.

You may want to keep the midpipe on. If they do total it, the cat is worth more than a midpipe for resale purposes. Reflashing the PCM shouldn't be necessary if the program was working properly before. From what I've read, the dealer shouldn't be able to tell that you have modified the program anyway.
You probably have a sensor that went bad or became disconnected from the impact.

my cat is at 45k miles, and i have the BHR midpipe i just paid 450 for....i thought cats were hard to give away here lol

Might be your exhaust mani??

Do you get any check engine lights?
Can you get them read at Autozone and post the CEL numbers here.

no CEL. granted i also dont have a CEL for my midpipe unless the base MM tune turns it off.