Gas pedal is very hard to push down and car turns off sometimes while driving. I've had this car for a year and it's never done this. What could be causing it?

SOURCE: 2001 hunday gx300 sputter when pushing on gas while driving or pa

QUESTION: "it doest while driving or park" ???? HUH? What you wrote is CONTRADICTIVE. Based on what you wrote, there's no telling what the problem is. It either DOES IT.. or it DOESN'T. Which one is it?
I'm going to assume you meant IT DOES IT while driving OR in Park.. is this correct? If so, then the possible causes are NUMEROUS!.. Let's verify - 2001 XG 300?.. correct? How many miles? 50,000, 60,000, 100,00 mile? Maintenance history? what repairs have been done and what hasn't? Your 2001 XG is equipped with an ETS (Electronic Throttle System) - this means that your accelerator is not DIRECTLY connected to your throttle. Instead, your throttle is controlled by a motor. In essenece, it is 'Drive by wire' throttle (not cable). The sofisticated electronics used to control your throttle plate is very complex... there are two critical sensors (which if they go bad) can affect engine performance.
Now here's an IMPORTANT question -- please read carefully - Does the Check Engine light come ON when this happens? Whenever the "Check Engine" light comes on, there is always a DTC (Diagnostic Trouble Code) stored in the ECM (Engine Control Module). You'll need an OBDII (On-Board-Diagnostics) scanner to retrieve any codes recorded/set in ECM. Once you do this and let us know what, if any codes are set, then we can go from there. If there is NO Check Engine light, perhaps the bulb is burned out (then you'll get a DTC of P0650 - MIL lamp malfunction). In any case, you either need to educate yourself regarding the systems incorporated into your vehicle (Go to http://www.hmaservice.com/ and register (vehicle by VIN). Afterward, you'll have access to technical information (manuals, wiring diagrams, service bulletins, etc) about your vehicle). This way you can possibility fix it yourself. OR Take/tow the vehicle into a Hyundai Service Center (dealership), pay the diagnostic fee. They will tell you EXACTLY what the problem is and what's needed to fix it (parts, labor, tax, time-frame, etc.).

SOURCE: rpms will not come down when clutch is engaged

The most likely cause of this is the idle control valve. This can be cleaned with injector fluid or similar (for little cost), but may have to be replaced. Either way it is not too expensive, and can be fixed in less than 1 hour.

SOURCE: No problem up to today.

Probably a stopped up catalytic converter, or a simple tune up.

SOURCE: Hi, I've got a situation

was the interia light on and battery flat