RTM
 

1999 goes into reduced thrust mode. I disconnect the battery let sit for 30 minutes, reconnect and runs perfect for roughly 30 miles. Can anyone help?

I would have the battery checked out . A bad battery can cause all kinds
of problems. That would be my first guess.
As you know even when your car is turned off there is a lot of electricity
running thru your engine powering the computers and nannys. A weak
battery can cause problems.
If the battery is good. I would check for a open cicuit like the hood light
remaining on or the glove compartment light remaining on.
Good luck