2001 Ford Explorer Sport Trac (Automatic 4.0l SOHC) I was headed to my college to take a final exam when my vehicle lost an enormous amount of power. I was going up an incline and noticed I was slowing down a bit and once my speed was low I dropped down to 2nd gear to make it the rest of the way (Past few months I've had to drop to 2nd to make it up steep inclines idk if this is bad to do- still trying to figure out accel. issue). This time when I dropped to 2nd my vehicle died pedals stiff etc and I pulled off the side of the road. Started back up, put in drive and had almost no acceleration at all. All the way to the house had no acceleration even on flat road and can't rev past ~2500 rpm. I've been researching a lot and have attempted to change/clean things, but so far nothing has helped. The only codes I get are P1120 & P1121 - both deal with 'Throttle Position Sensor', which apparently my TPS has not been functional on the vehicle for a year+. Other Symptoms: -Stiff pedals (No crazy stiff, but noticeably stiffer) -Crazy Low acceleration -Max Speed (Flat surface) ~30mph Other Recent Events -Went in 4wd for the first time in years just prior to this Any help or suggestions will be much appreciated.