Possibly. An ideal 2-way splitter would deliver half the input signal to each TV. A real one delivers a bit less than that. A TV needs a certain minimum level of input signal (and signal-to-noise ratio) to work; if the splitter delivers less than that you'll get no picture or, if it's right on the edge, pixelation, freezing and audio dropouts.
If the antenna signal is sufficient for one TV you can add an amplifier before the splitter to compensate for the splitter loss. But try a good splitter first. They're not expensive and it might be all you need.
Everytime you split the signal you lose 3db. I have an 8 way distribution amp with active return (zero loss) and I have no issues with that on my cable. You may want to look at something similar to maintain consistent levels.