The car is a 1991 560 SEL. I have also measured the ohm of the cis/ezl temperature sensors and they are where it need to be.

If I let the car coast around 40 MPH, I could see the RPM coming down to ~1200 then suddenly jump back up to 1500 RPM. When I just park the car and shift to P, it will be at 1000 RPM for about a couple seconds then go up to 1200. It just seems the car want to idle but something is telling the computer to go to a higher RPM.

Could I just drive the car like this? Start up in the morning, 1000 RPM at P, stop at red light, 750 - 800 RPM in D, and arrived at work 1200 RPM on P. It is about 200 higher than spec in D.