I need help!!! I put a aftermarket radio in my 2002 Monte Carlo SS and didnt disconnect the battery so the anti-thief went off. Now it’s not throwing no gas so it’s not starting!! Everything turns on but now it don’t start!!!

 

Unhook the battery and let it set for a couple of days then put the original radio back in it and try it again.
I read someone did that and he had some success.
Chevy runs everything thru the Radio and it can be difficult to get the thing working again when it gets changed.
Hopefully you refrained from cutting wires.