What is this air line here (see picture)?

There is a little rubber boot that somehow connects the small clear plastic line to the larger one, and this popped off on mine. I messed with it for a few minutes but not exactly sure how it goes back together.

Anyone have any pro tips?




Rubber adapter/boot is the upper/left arrow. Plastic line is lower/right arrow.

 

I don't know the answer, but have to comment on the fact your engine bay is spotless compared to mine. I'm jealous!

 

I guess it really is that simple. Looks like my boot/adapter was worn. Popped a new one in there and the fit is nice and snug.