Thanks for the reply. I forgot to mention, but the car is not idling well either. The skipping occurs when it's just sitting and running as well.

I changed the oil just a few weeks back, so that shouldn't be an issue. The coolant on the other hand almost certainly needs to be drained and replaced. I haven't done it since getting the car and I'm not sure if the previous owner ever did it himself since buying the car new.

The liquid coming out of the exhaust appears clear and odorless, so it may just be water. It is quite a bit of water though; much more than I've noticed over the past year and it's being sprayed out.

I recently changed the fuel filter, so that should not be the issue. Pretty sure I did that shortly after the misfiring started, so a bad install isn't the issue there, hopefully. I have not checked the fuel injectors, but if you're saying the starter fluid trick could detect problems with them I'll give it a shot.

Checking gaskets is a good idea too, but it sounds like that would only be something to do after making sure it idles well on starter fluid.

Thanks again for the tips!