Spark Plugs pregapped DONT BELIEVE IT!!!!

[blueoval9erlifer]

Changed the spark plugs, boots and springs in my 04 xlt 4.6l this weekend and was told when i bought the plugs did not need the gapping info from the parts store because they are pregapped from the factory. I always check this anyway but my gap is supposed to be .052 to .056 the new plugs were all at .040 old ones i took out 91,000 miles on vehicle ( i just bought it) were all at a .066 to .070 just worn down from driving. Guess what im saying is to always have a gapping tool available and double check because the factory setting for this is obviously not right.

Also swiss cheesed air box put 5 1 1/4 inch holes in it to start with and seems to make a difference ill know more in a couple of weeks but i wish i had done this alteration after driving with new plugs to see which makes a bigger difference in mpg.

 

[Joe Dirt]

No way I would ever trust a plug to be pre-gapped correctly. Well, they could have even been gapped correctly, but in handling, those things are too easily bumped.

 

[SyberTiger]

I've heard that silliness before about pre-gapped plugs too. Like y'all said you should always check the gap yourself. Just think about all those cars that go to the dealer for a tuneup and end up with pre-gapped plugs. Oy vey!