I had the same problem. Turned out to be the heat shielding on top of the muffler. ItÆs only tack welded on each corner and over time the welds break loose.

When your Sportage has been sitting over night and your muffler is cold get under there and try lifting up near each corner. You'll probably find at least one corner is loose.

I had a muffler shop tack weld it a couple of times, but after a while it broke loose again and while doing 65 mph down the freeway the entire heat shield came off and went out the back. <img src="/forums/images/graemlins/scared.gif" alt="" /> Luckily there was no one behind me.

Logansportage <img src="/forums/images/graemlins/patriot.gif" alt="" />