95 neon, High Idle?!

Ok, its been about two weeks since I posted this on here. Im starting a new post just to make it easier for everyone to see what has been done up to this point.

I have a 95 neon that is running a very high Idle. When you remove your foot off the break & gas it idles around 40 mph. Iv just replaced all the breaks and its melting the new ones already. I am receiving the following check Engine Codes: 12, 25, 32, 15. I have completed the following repairs:

  1. replaced all vacuum lines.
  2. removed EGR Valve to clean, replaced all lines. No more engine code 32, however, now I am getting engine code: 12, 23, 25, 15.
  3. removed intake manifold to replace the PCV Valve as well as all hoses from the oil separator.
  4. replaced the IAC sensor
  5. used ohm meter to check all wiring from IAC to computer. no issues.
  6. replaced the TPC sensor
  7. used a ohm meter to check all wiring from the TPC to the computer. No issues.
  8. used a ohm meter to see if the air temperature sensor was working correctly. No issues
  9. checked wiring from Air temperature sensor to computer, no issues.

The car continues to idle extremely high to the point it is not safe to drive. By feeling the throttle body where the IAC lets in air, it feels like its comply open. I pulled the IAC out of the throttle body while it was plugged in and ground to the engine block. When you turn the car on you can see the IAC move, but it never seems to want to shut off air supply.

It appears the computer is telling it to let more air in even though its very high idle. I replaced the computer about 5 years ago. what would cause this?! Im to the point iv put in way too much time and money already. but I don’t want to buy a new car when it could just be a $50 fix. Please help me!

Check the wiring harness that runs along the back of the engine.

I had a friend who many years ago owned one of these vehicles. And the thing would turn the Check Engine light on but instead stall out.

It was found the wiring harness had lost it’s plastic retainers from heat and was leaning against the engine, melting the wires.

Tester