2004 Acura TL Engine Light

Hi,
I purchased the above vehicle on 9/24. I drove it home, about 80 miles and the vehicle seemed fine.
However, late that night when returning home from my friends house, the engine light went on and the vehicle lost power, and acted like it wanted to stall.
I drove it back to my friends house and parked it.
The next day, took it to auto parts dealer, for a diagnostic test and the test showed throttle problems. Before purchasing the vehicle, my friend and I asked the salesperson about a throttle part replacement, since the part looked new and the salesperson said he did not know if the part was changed recently or not and did not know what service their shop did either, even though I asked him several times.
My question is: Could the dealership have reset the engine light? About how many miles would the vehicle have to be driven before the light came on again. I drove it 115 miles only.
I do not think the dealership serviced the vehicle at all, as the reservior for the antifreeze was not filled at all. If any of the fluids were checked, then the antifreeze container would have been filled to the proper level.