Even if the filter was what caused it, and blowing it off solved the problem, the check engine light would still stay on. It took my check engine light a few days to clear after solving all of my problems. I doubt that's what it is though. Your best bet is to have the salesmen look at it. After he tells you he's fixed everything, take it to a shop and explain the issues and they should look at it for free, find out what's wrong, and give you a quote. Take the list of issues the shop found to the salesmen, and tell him to fix it again.
