Is the throttle pedal binding on a floor mat?

Next take a look under the hood, follow where the throttle cable pokes through the fire wall, it might go to a throttle position sensor just ahead of the brake master cylinder, see if anything is binding there. This a drive by wire system.

If the cable goes towards the engine, there is a complicated linkage system under the intake manifold that might be binding. Does this car have a switch that looks like a snow tire or marked ASR? If so, these systems pushed back on the throttle when rear wheel slip is detected.