126K. Runs fine, still getting great gas mileage. Not sure what changing plugs now will do for me other than empty my wallet of $500...

Have the plugs already been changed once?

no, original

Hmmm, probably time. I've run extra miles on plugs and as a general rule, once they get near to end of life you'll start noticing things like a subtle miss every now and again.

OK, thanks for the info. I'll look into it.

Changing the plugs is not as ulcer triggering as it looks. There are 2 bolts that need to be remove when taking the upper intake manifold off, that are not easy to see. First one is under the throttle body, 10mm head. The second is located almost dead center of the intake, near the firewall, behind the intake. Everything else is just nuts, bolts and time. Once the upper intake is off, access to coils and plugs is easy. Pick up new gaskets for the intake, 6 oddly shaped rubber seals, and replace them while your in there.

Thanks for the advice. I'm not much of a mechanic but it sounds simple enough. I called several shops (dealers and independent shops) and they all quoted about $450-500 for the job! That means they are charging about $380 for labor as the plugs and gaskets can't be all that much. Even the Iridium plugs are only about $8 each. I heard it's about a 2 hour job but sounds like the shops are figuring on 4-5 hours labor rate. I know they need to make a profit but this certainly seems excessive to me.

Mitchell labor quotes 2hrs. Give yourself 3-4 only because it's your first run. Vacuum hose on back side of the intake has a clamp but slips on the valve cover so don't fight with the clamp. You can give the throttle body plate a good cleaning with carb spray while you have it off. 126K on plugs you say? You'll feel a difference. Performance deteriorates slowly over time and you don't really notice it. But when you freshen it up, you notice that right away.

Good point. I still get good gas mileage but hopefully I'll notice an improvement in performance. Thanks