Do our trucks have a filter in the vapor canister?
 

While looking for other emission parts, have seen a couple of listings for a round flat filter listed to go in the vapor canistor. They are cheap, just a couple of bucks, looks like what you would expect if you used a coffee can to cut a round piece out of your home AC unit filter.

I've looked at my vapor canister, doesn't look like you can open it up. My truck is an 84, the canister has 4..uh.. conection things on top, some with two hose.

If the canister has a filter that can be changed, how do you open the canister??

I have cut one open before and yes, there is a filter on the top. But, you notice I said cut one open. There is no way to open it and reuse it. At least my 85 was this way.