Why does my accelerator keep sticking until the engine has warmed up after 5 minutes?

Year/Make/Model

I'll take a stab at this even though we don't know your make, but a general throttle body cleaning will take care of this issue.

Just had a '00 Rav4 in today. The complaint same as yours. When I drove it, the problem persisted at every let off the gas.
Very annoying to drive. Back at the shop, a very wise customer decided to go ahead with the throttle body service.
Problem fixed!