Long story short car was running fine. It was running a little rich at 13.6 I noticed my o2 sensor wasn’t plugged in. So I mistakenly plugged in the o2 sensor not noticing the damaged to the wiring. I turn the key to power and I see smoke by the ecu. I immediately **** it down.

Now the car only cranks. I’ve changed the efi relay, added new ground wires to engine, and used a different ecu.

I have to check if the ecu is getting power. I know I’m not the only person this has happened to. Any suggestions