01 SOHC 88,000 . When you first start it up it idles at 2000 plus for a few minutes before it idles down. Then when you take off it idles back up and takes off on its own until is eventually drops back to normal but as you are driving down the highway you can let off the gas and it will maintain speed you can even pop it in neutral and the rpms will increase up to 3500 all without your foot on the gas. I’ve cleaned the throttle body and MAF and have replaced the IAC,TPS and PCV with no change.Any ideas??

 

Do you have any codes?