Alright guys, I'm new to all this stuff so I need help. I have a 2006 Scion XA. I went to fill up with gas two weeks ago and about five miles later my check engine light came one. I went to a car service place and they reset it. I changed gas brands because a friend told me that her light came on if she used cheep gas. It's been 200 miles now and it just came back on yesterday. The car passed inspection last week fine. There haven't been any modifications made to my car. It has a little over 25,000 miles. I've searched the forums but any topic about a check engine light has to do with someone altering their car.
Can anyone tell me what might be going on??? I'm going to take my car to the dealership Saturday but I would like to know what I am in for.
I appreciate any help...

 

maybe it needs an oil change, because the light comes on every 5k miles and that reminds you to change the oil.

 

it can come on sometimes if you don't tighten the fuel cap enough. it can be cheap gas, go and look up who sells top tier gas.

but it doesn't matter, 25,000 miles and it's an 06, your completely covered by warranty.

 

make sure you tighten the cap until you hear a loud snap. any less and you can get a check engine light.