Ok i think i might have found the issue, not sure. When i went to install the E3 plugs when i first got the truck (81,000km) the original plugs looked like this...
So when i went to change the plugs, i noticed #9 was really hard to get out. Finally after alot of cursing i got it out. But then when i put the new E3 plugs in, it kept cross threading. After getting it to somewhat not cross thread i got the plug in, well it looks like i didnt get it in all the way, even though that sucker was cranked on.
So today, dispite the blizzard we are having i went out and started changing the plugs. #4 didnt look bad at all. Once i got to #9 it looked totally different then the others. Heres the pics #1, #4 and #9
Those plugs have just over 6000km on them and as you can see, not much of a difference between #1 and #4. But #9 was burned at a higher spot then the others and not sure if you can see in the pictures but you can tell how far it was tightend down. I put all new NGK plugs in, gapped at .045, but #9 is feeling like its doing the same thing when i tighten it. It gives resistance but keeps going. I dont want to keep going because i dont know if its stripping the threads in the head (if they arent already stripped) But it defently doesnt feel normal. I started the truck up, got it warmed up, seems to be running fine, but then again, it seemed to run fine all along.
So what do you guys think? Could the #9 plug that wasnt in all the way cause the cylinder and #4 cylinder to misfire? Any way of repairing the threads in the head or do i need a new one?