is there any way to check it other than taking it to the dealer? Reason I ask is I fixed all the other stuff in my earlier thread but I do not have the acceleration I previously had and I can hear spark knock. I'm thinking maybe the timing belt jumped a notch from a couple backfires but I don't want to start taking things apart if there's an easy way to check it.

Are you thinking cam timing, or ignition timing? Cam timing being out sets a code (or it did for me) and changes your power band, usually for the worse. Ignition timing is non-adjustable but if you found a way to do it I'm sure there are lots of people here dying to find out how, as am I. Crappy gasoline can cause your car to run like a bag of $**t, did you fill up somewhere you don't normally? Also there is a knock sensor just ahead of your oil filter, on the passenger side of the engine, that may be unplugged or malfunctioning. These are just some random ideas as I have to go drink beer now. Good luck!

Fixed!!!! Wasn't the timing, the second catalytic converter was plugged. Good thing we don't have emissions tests in Michigan.

How did you find out your cat was clogged?

I'm curious because I suspect mine could be.

Also how many miles do you have on your Sportage? You're making me think, mine is a 2002 and yours is a 2001 so maybe mine is old enough to have a clogged cat too...

I've got almost 170,000 miles on it. I started losing power over 3000 rpm, and top speed was about 70 mph, took a long time to get there too. It still started up and sounded like it was running fine though. I did have to keep my foot in the gas to maintain speed and would lose speed going up even small hills. The motor was working a lot harder and sounded like it, and I'll assume that's why the spark knock, because of the load on the motor trying to push exhaust through something that was plugged.
The front one got plugged up a year or so ago and a guy I worked with suggested checking it, removed the honeycomb out of it and it ran fine. Started doing it again last week and it took me that long to remember what I did last time to fix it, so now the rear one is minus the honeycomb.

If you're going to check I'd go with the front one first.

What does the spark knock sound like?

My Sporty only has about 70k miles on it.

Kinda like a slight fast rattling/spark noise.