I just checked my spark plugs and they looked like the original plugs and if so they had 72,000 miles on them. The gap was .065 and should be .045. Anyway I decided to replace them and do an oil change. The parts store only got me 4 so I went ahead and replaced 4 and did the oil change. Right after doing this the engine light came on. Any ideas way? Can I reset it and what is the least expensive code reader for my truck? It's a 2004 5.7L.

Thanks,

 

What was the code for the CEL? Could be something related to the plugs and might not be. Need the codes to know for sure.

 

as weedahoe said codes would be good to know if you don't know how the check it you just turn the key on and off 3 times in a row leaving the key in the on position after the 3rd time without starting it and the codes should show up where the odometer is.

 

If you have an autozone nearby they will read your codes for free.

 

why would you change only 4 plugs? gotta get the other 12 and get em done. I wouldn't mix new and old plugs.

 

That didn't work for my truck so I purchased this http://www.actron.com/product_detail.php?pid=16318

I replaced the rest of the plugs but the light is still on. I'm assuming I will need to reset the computer after I retrieve the codes. I will let you all know which codes show up.

Thanks,

Steve

 

Yeah the key switch trick doesnt work on 04s

 

I purchased an Actron CP9180. Wow what a nice tool. The code came up as P0441 Evap Control system purse flow fault. I found this description on OBD-Codes.com but it doesn't appear to be related to spark plugs.
Anyway I finally replaced the rest of the plugs. I didn't realize there were 16 until nh5 metioned it. I also cleared the code and it hasn't come back and it's been a week now so I hope all is well.

Thanks,

 

Gas cap loose?

 

Probably something origanally left loose when you were doing the sparkplugs