I picked up an '06 TJ X Model a few months back. It ran fine, but seemed incredibly flat under acceleration. I wrote it off to 33" tires and 3.73 gears (which will be addressed soon). Since it had 106K on the clock, and I had no maintenance history- I'm going through the whole rig. New brakes, new tires, new fluids, AC recharge and I finally got to the plugs. They were pretty worn, but the electrodes weren't burnt off or anything like that. I switched to a set of Champion Iridium plugs and the difference is actually shocking. It runs much smoother and the acceleration is finally almost tolerable. My niece drives it to work lately and she even texted me asking what I had done to the Jeep.
Long story short, if you can't remember the last time you changed plugs or you have no idea if they've been changed- check them out. I wish I had done it months ago. $50 and 1 hour of time made a HUGE difference.
Long story short, if you can't remember the last time you changed plugs or you have no idea if they've been changed- check them out. I wish I had done it months ago. $50 and 1 hour of time made a HUGE difference.