Engine goes into limp mode and I must push the accelerator almost to the floor

It sounds like your transmission has been on its way out. the transmission computer automatically adjust to worn internals of the transmission to provide the driver with the most normal feeling shifts. When the computer can no longer adjust the shift pattern for a worn transmission it goes into "limp mode" and the transmission stays in 2nd or 3rd gear and won't shift into any other gears.. this is the reason for the additional effort to get the car to accelerate. Give us a call if you have any other questions, or would like to set up an appointment to have it looked at.