Hey, I'll try to help but it sounds like you got a mess
#1 a knock sensor should be a one wire sensor, I have never seen one with two wires. The knock sensor is simply a sensing device, and when viberaion is sensed, the ECM takes away timing.
#2 Dont know the ECM reflash but I dont think so, may have to get a 2000 computer
#3 The park/neutral switch circuit is closed when the vehicle is in P/N, so if you attempt to start the vehicle in D, it wont because power is passed through the park/neutral switch first.
Where is the wire connected to under the fuse box, what fuse, and what does that fuse control.
Do you power at the park/neutral switch, with the key on?
The starter should have two wires going to it, one from the battery, and is the other is for the solenoid
- 2004 Cavalier - 124k, owned since new