Greetings,
After approx. 28,000 miles the Service Engine Soon light on my wife's 2003 Sorento went on last week. We noticed a decrease in mileage and at least one episode of hard starting. We called our dealer and made an appointment to have it looked at today (even though the light went off yesterday morning). Our dealer called us back this afternoon and gave us a report on what was wrong - the computer sensed a misfire and we had two bad spark plugs and a bad coil, all to be covered under waranty with no cost to us. In fact they are replacing all of the plugs and wires just to be sure. Funny thing is that since the plugs were rated for 100,000 miles, the dealer didn't have any in stock so they will get them tomorrow. No problem for us, but I looked into replacing the plugs a few months ago and they were so buried inside the motor that I didn't want to try it myself so better to have them do it for free.
And another interesting item - while the truck is in the shop we also wanted to have the fuel filter replaced. It is inside the tank and takes about an hour to change (definitely not as easy as my Chevy), but the service manager called back and told us that it was an integrated one-piece unit and isn't serviceable without changing the entire unit, but it didn't require any servicing unless we were actually having a fuel flow problem. I guess if they want to talk themselves out of making money off of us then that's fine by me also.
Cheers - Jonathan