2005 f150 fx4 5.4 ltr 141,000 miles

Code PO304 (cylender4) keeps poping up on coder changed plugs and COPs. PO304 pops up again. Changed COP and plug with the #2 COP and plug still shows PO304. Missing when in overdrive take out of overdrive runs ruff then smooths out.

 

Check your fuel pump driver module above spare tire on frame rail. If corroded, replace and see if that fixes it.

 

All the usual stuff may smooth it out enough to stop misfiring and clear the code. I would start with FPDM (as said), fuel filter, air filter, clean MAF and throttle body, then once you are done all that, maybe look at injectors.

 

If not the module check the intake manifold gaskets.

 

swap #2 and # 4 injectors...

 

Ok. I'll give these things a try. Thank you. I have not switched injectors. Am replacing the #4 injector this week. Thanks again. I'll keep y'all posted.

 

If your going to replace it...don't bother swapping it...just trying to save you a little money...instead of throwing parts at it

 

Ok here it is.
This past Saturday went approximately 30 miles, the truck bogged down and started missing 5 different times. After returning home I unplugged the fuel pump modual, reconnected it. Drove approximately 40 mile the truck bogged down started missing 3 different times. Truck sat all day Sunday. Drove truck to work approximately 80 miles round trip. No problems. Same Tuesday no problems.

 

Now the left front blinker ( turn signal) not working. All fuses show to be good. Any suggestions. ??????

 

Look at the bulb on it.