My 1999 kia sportage glx se is misfiring but still drives,there is no warning lights on dash no engine managment light on either, would this just be the spark plugs ot the spark plug leads that is causing the misfiring

Check your fuses the one for check engine light might be bad. Every time I had a misfire with my Kia the check engine like came on. You may also take it to an Auto Zone or a store that checks the computer of your vehicle for free. If it is a misfire there are a few remedies I know of

First if you haven't changed your spark plugs in the past few years you should look at replacing them.

Second older vehicles the gas tends to get sediment in it because you are not using all of the gas in your tank even if you run it out. I found that out because it would drive fine until I filled the tank up which in turn churned up the sediment from the bottom went through my gas line and caused a misfire. The easiest way to fix that is maybe a gas treatment which may break down the sediment. The harder and more expensive is drain the tank change the pump and the fuel filter. You don't need to drain the tank entirely to change both but it defeats the purpose of change both and still having sediment in the tank.

Third in order get the computer checked, change spark plugs, have leads checked, then use fuel treatment. Just so you know when you use fuel treatment it will run a little rough at the beginning because the sediment is being broken down give it a week or so to let it run its course.

good luck