I went through and did a basic check on my motor today just because i had nothing better to do and I got to checking the plugs. Facing the car i pulled them out of the head starting from the farthest left and worked my way right. the first 2 seemed fine.. but when i pulled the 3rd it had some carbon build up on it... i thought it was odd.. but couldnt really see any build up on the piston. So i put it back and pulled the 4th... there was quite a bit more build up on this one and it looked A LOT whiter then the others? Once again i saw nothing on the piston? so what would cause this?

 

Wow.... no one has anything to say on this matter?