If a video game utilizes FMVs a lot then a malfunctioning codec CAN cause problems.
However I would say the likelihood of a codec pack causing a game to not work is pretty slim. Games are less and less dependant on FMVs to show things, prefering to do them in engine, and as long as you operate in engine it doesn't matter what codecs you have loaded, except for maybe sound, but those are even more rarely the cause of issues.
You can TRY uninstalling the codec pack to see if it gets rid of a problem, but if you are not currently experiencing a problem, then removing it won't help at all.
The types of problems a bad codec can cause are crashes at startup when it plays the intro cinematic, Crashes when FMVs load, artifacting or ugly FMVs, or a blank screen during intro movie or FMVs. If it isn't one of those things, it is extremely unlikely to be a codec pack causing your problems.