2013 Focus Platinum broken cold air intake

[Seanb.73novacustom]

My buddy in college has a modified 2013 Focus Platinum he bought from a dealer about 4 months ago, and spent 1500 bucks at a dealer since to not really fix any issues. One of the many issues is the k&n cold air intake. The rubber boot that connects the filter to the air intake pipe is torn so no matter what you do, after less than 2 miles the filter falls off again. I believe this is leading to a dirty maf which I think is why it runs like crap and is rich according to the codes it’s throwing, but either way it obviously needs to be fixed. He doesn’t care about having a cold air intake, and already has way to much money into the car so I’m trying to get everything fixed for as cheap as possible. Does anyone know if they sell just the boot for it? If not, what would be the cheapest way of replacing it? I’m a classic Chevy guy so I don’t know enough about what I’m looking at in a modern Ford to tell what all is going on so any help would be appreciated greatly