Have a 07 that has a miss fire code on cyl 5. I put in new plugs and wires , ran great for about 400 miles. Now it came back. I moved the coil and wire from cyl 5 to cyl 1 and still has a code for cyl 5! Any ideas?
code is P0305
thanks

 

Did you try swapping the plug or install another new one ??…I’d worry about a bad plug before a coil pack or plug wire…the “coil near plug” coil packs are pretty bulletproof…odd that it ran OK for 400 miles and returned…sometimes it’s not always the cylinder that your scan tool shows…could be #6 or #4…the cylinder before and after #5 in the firing order…sometimes the crank sensor which is the misfire monitor is not always right…it could be mechanical or an injector…what do your long term fuel trims look like on bank 1 ??…an injector misfire will have trims around 15% or so since there is a lot of oxygen in the cylinder…if that high you can try cleaning or replacing but I would first check the injector wiring…one wire is power and the other is “ground side switched”…ECM will ground that wire to fire the injector…you can check that with a test light connected to B+ and see if the test light blinks when probing that wire with the engine running…now it can also be wiring for the coil pack too…as far as mechanical without using a compression gauge hold the gas pedal to the floor and keep it there as you try to start the car…it will only crank so listen how the engine turns over…the cadence should be nice and even…BTW your profile shows a 2000 so might want to change that and include as much info about the car…model year, trans, mods, tune etc…

 

Move the coil pack and see if problem follows it.

 

​​​​​​​If that does not work try swapping fuel injectors.

 

Says he already swapped coils so I would suspect the injector.

 

, while removing the rail I found that spark plug wire fell off the coil on cyl 6!

I moved the injector from cyl 5 to cyl 2 anyway.

just drove 80 miles, ran great no codes

thanks to those who made suggestions