CEL is on, and questions about warranty
 

Ok first of all the other day my check engine light came on, So of course I kind of freaked out and was scared, so I drove the car to Advanced Auto parts and checked the CEL codes and then checked them to see what they meant

I got the following

P0301 Which I think was a misfire in chamber 1

and then something about a small emissions leak. I believe P0405 (I can't find the paper I wrote down the codes on)

The question is my car JUST passed the 40,000 mile mark, as its sitting at about 41,000 miles. Will the dealership still cover this, and what kind of mind games will they try to play, like what will they try to upcharge me for, like we all know how they say they will fix something thats $500 and that won't even be the problem, any help would be appreciated.


Also I assumed that while these are problems I need to get fixed, I thought the misfire was due to the spark plugs, and I was going to wait to get that fixed, but I dunno about the small emissions leak.