Mitsubishi Repair Problems? Ask a Mechanic for Answers ASAP
Before doing anything else I would get the engine light checked to see what the computer is picking up as an issue. It is very likely that there will be a relationship between the engine light code(s) and the drivability issues you are experiencing.
If the fault code is unrelated, then I would want to check your basic maintenance items (tune up current, good gas in tank, throttle body is spotless inside). If nothing unusual is found there and everything looks good, then I would proceed with more intense research which would require a full function scan tool. Specifically logging the TPS signal while the engine is off to look for dead spots and data logging while driving to see what the sensors are doing when the problem occurs to help hint at what is going on.
Again before doing anything though I would want to scan the computer to see what is turning the engine light on. It is highly likely you will find something that could be relevant to the hesitation.... a TPS fault, misfire/lean fault, etc. Once the engine light problem is fixed and not returning, then I would want to start evaluating the driving condition once the computer effectively gives the all clear.