I have had the car for about a year now, I don't have any miss or stumble, but I have no clue as to the age of plugs in the car. A friend of mine tried taking a plug out while we had the car in the air and he was having a tough time trying to get it out. He was able to unscrew a couple turns before it got tight, screwed it back in and tried unscrewing it again. He tried a different plug with similar results. Like I said, I don't have any stumble or miss or such; but, I am thinking about changing these plugs some time soon just for ease of mind.
He said it almost feels like carbon build up on the end of the plug is causing some sort of hinderance. Has anyone experienced this sort of situation? I'm concerned about putting too much torque on the plugs and breaking them trying to get them out. What can be done to try to get these plugs out without breaking them off?

 

spray them with Liquid Wrench or PB blaster.