04 solid check engine light

Just got my 04 taco two Thursday's ago from a reputable dealer. After running the first half of the gas tank through it, that the dealer had provided a check engine light came on. I bought the truck as is with no warranty. I contacted my salesman and he said I could bring it up to get looked at. If it is something major or minor will they cover it? If not any ideas of gettin there asses to cover it? Also if anyone were to guess what it is, what would you say? It's a solid light, gas cap it tight, runs no different than the day I got it. It's got about 117k on her. Thanks for any advice or knowledge .

 

go to autozone and get them to read the code and post up here what it is. could be a few different things.