emission

I noticed that there is a sharp smell coming from AC if I accelerate suddenly. It doesn't smell like gas or anything I can match but it is sharp and of course it goes away as the RPM lowers. I'm curious what might be the reason. Recently the check the engine light turned on due to emission...

I've been having trouble with my 2001 century buick, to figure out why those lights turn on after I move the car, sometimes they turn off, but sometimes it stays all day, my emission line just broke as well does this have anything to do with or are these two separate problems, I want to fix it...