My wifes 2003 F150 (5.4) started running rough, whether driving or at an idle. The code that I am gettting is this, BANK#1 too lean & misfir cyl #2. I changed the spark plugs out about 30k miles back. I have changed some of the COP's but no positive it this is one of them. When the others failed they didn't have the same symptoms. They would only run rough once I got into overdrive and was attempting to climb a hill or something of that nature. I know those were only weak, and this COP may have completely failed. Anyway I didn't know if the BANK#1 too lean code was a result of the misfire or the possible cause. I would appreciate any tips on trouble shooting this problem.

Thanks in advance

 

Number 2 cylinder is pretty easy to get to, unplug COP while running note change, then unplug injector on 2 note change, listen for click noise on injector running with piece of hose , this means power to it, still no luck , swap coils with cylinder 1, note code movement, no luck ,swap injector with cylinder 1 and see if code moves, you'll find it

 

Fix the misfire first and see if the lean code comes back.

 

Thanks for the response. I will try the tests you recommended to try and determine which is causing the problem. I didn't know if there was a way to test the COP with an ohm meter but since it is fairly easy to get to #2, I with follow your advise. As far as fixing the misfire and then checking to see if the lean code disappears. I would assume that a misfire on that cylinder could be caused from the injector or the COP, so I was wondering if there was a trick to testing which one was causing the problem. Swapping them both one at a time with a known good should work.

thanks

 

Injector ohms are 13.5 to 19 , COP ohms are .55 ohms primary (conector terminals) and 5,500 ohms secondary( primary terminal to plug spring), fyi all could be good and still misfire due to clogged injector

 

Thanks for the info, I will test the both of them and see what the resistance is and go from there.