I was having some misfiring issues and the check engine light came on. I went to Advance Auto and they hooked it up to the engine analyzer, it said that cylinder 3 and 4 coil over plugs were bad so i replaced them. It ran great for 2 days now the problem is back and had advance check it again now it is cylinder 2 COP.
Will this start a chain reaction of COP issues?
Also there was a little moisture on the #3 COP before the replacement.
NOTE all these problems after replacing the spark plugs (with motor craft plugs)
need feedback
2003 f150 5.4

 

Are you using di electric grease on the COPs? Sometimes it's bad luck that COPs will start to go all at the same time if they are all old and on their way out. Unless you get repeating codes on the same cylinder I wouldn't think injectors. On a side note what did you torque your plugs to? 28 ft/lbs is the new standard to prevent problems and blowouts.

 

I torqued everything hand tight with a 3/8, didn't over tighten. Also used di-electric grease on everything. The truck only has 125,000 miles on it. Do you think its worth bringing it to ford and getting the real engine diagnostic or spend the same amount of money and replace all the COPs. Also are the fuel injectors hard to replace and what kinda money are we looking at? Thanks for the reply.

 

Ford's OBD diagnostic will just pull codes the same as advanced. I would replace the packs as they go bad and keep going. See link for COPs. I would think if it was injectors you'd have a lean condition on that bank also, but a bottle of PEA type cleaner (Techron or Gumout Regane) through the system won't hurt anything and give you peace of mind.
http://cgi.ebay.com/ebaymotors/IGNIT...ht_1717wt_1165

 

I put Sea Foam in the tank. But what a pain changing those things with a lift on the truck have to get out scaffolding lol once again thanks for the advice. Just recently found this site, "what a help" thanks otto