Gas pedal is hard to depress - 2003 Buick Regal

I have had this issue on many GM cars before. Some background on GM cars have problems with the gas pedal spring being way to stiff or becoming stiff over time. I would suggest you go to the auto parts store and pick up some White Lithium Grease Spray from CRC like this...and locate the springs on the under side of the gas pedal and lube it up.

I would agree with the other poster that you should clean your throttle body as a maintenance and upkeep measure, but on late model cars, your gas pedal is hooked up to a sensor which sends signals to a motor on the Throttle Body to open and close the flapper. On older cars, there was a wire that directly connected your gas pedal to the throttle body. This is not the case in your year car.

Here are some basic instructions for cleaning the throttle body.

1. Open the hood, look at then engine.
2. On the right side there will be an air intake tube that is black and hooked up to your air box and throttle body with hose clamps
3. Losen the hose clamp from the throttle body and remove the black air hose from it and gently move it out of the way.
--> If you do not want to remove the throttle body completely, skip to step #7
4. there will be 4 bolts holding the throttle body to the intake manifold.
5. Note any and all electrical connections to the throttle body.
6. Remove the electrical connections (unplug) and remove the bolts (4) and the throttle body should come off.
7. Spray CRC Throttle Body Cleaner all over and wipe clean with a cloth that can get really dirty.
8. Make it SHINE :) then reinstall
9. put 4 bolts back on, reconnect the electrical connections you remembered from step #5
10. Reconnect the black air hose and tighten the hose clamp...

Done!

Do you baby your car ...if so usually the throttle body gets caked up with gunk i would recommend to take off the TB and clean it ...this should solve your problem ...