AC filters???

1. They probably can't, but I can't say for sure.

2. Probably not, but again, I can't say for sure.

3-5. I dunno.

I do know, however, that places like Jiffy Lube try to get you to replace your air filter (for the engine) every time you get an oil service, whether it's a new or old air filter. It's one of their simple ways to make money off people who don't know any better and want to be on the safe side. In their defense, though, sometimes people really do need new air filters.

I would guess the AC filter is the air filtration system for pulling external air into the cabin. I would imagine that there would be one filter used regardless of whether there's AC or heat. Perhaps it's not actually an air filter, though....is there the possibility that there's any filter on the AC system itself, like an oil filter? If so, there may be a way to tell it's bad without getting to it, just like you can see whether your battery is dead or the AC needs a recharge from the little viewing window.

Whatever it is, it's probably not urgent enough to get fixed today....

b