Do I have a transmission proble?

Question

car won't accelerate.  have to floor it to go 25 at times and the rpms go high.

P1599 code
P0125 code

Answer 1

P0125 Engine coolant temperature not at closed loop operation

P1599 Engine stall when the ignition was not turned off

If this is a manual transmission then yes you have a slipping clutch. P1599 is most related to a engine stall with a manual transmission as in putting it in the wrong gear and the engine stalls. Having a high RPM just to go 25MPH is a indication of a slipping transmission