Random miss fire need HELP
As long as both O2s are disconnected all bets are off. You're going to stay in open loop. Even after your ECT comes up you still can't control your AFR. You can leave the rears out for now if you want. You're going to still get the rear DTC, but you MUST get the front ones working. Then you can start troubleshooting the P0300. If you hook up the front O2s the random misfires might stop. You'll never know until you hook them up. If not, you have to look for something in common to ALL 8 cylinders since it is random. The ECM can narrow it down if one particular cylinder stands out, but yours is all over the place. Start thinking about what sensors are common to all 8. Connect the fronts and work from there.
