OMG need help fast

So, when you pull the #2 wire the popping stops. Does the engine sound better (ie, not as rough)? Obviously it will be down a cylinder, but if the "problem" goes away, you can pretty much rule out a timing chain. It may be shot at 91,000 miles, but you'd be missing on all the cylinders (or more of them), not just #2, if it skipped time.

Check the compression across the board, see if #2 is different. If it isn't, go back to the ignition. If it really is isolated to #2, you're looking at a wire, a plug, or maybe an issue at #2 at the cap.

If the compression on #2 is down, based on what you're describing, I'd go with a stuck/burnt valve, or maybe a rocker problem. It might be a cam/lifter problem, but I'd put money on a valve at this point. Squirt a little oil into #2 and see what the compression does just in case, it should come up a little (10 psi or so), but not all the way back to normal. If it does come back to normal, its rings. If it doesn't you're back at the valves. The good news is, even a small piece of carbon deposit can hang a valve open, and it doesn't take much. Bad news is with 91,000 miles and unleaded fuel, that's probably not what it is.