2006 F150 with the 5.4 V8 - Recently replaced all plugs and coilpacks; however, after a month I went to start the truck and its shaking like a tractor and I don't think its drivable. Ran a scan and came back with an P0303 code tried swapping out the coil for a new one and no improvement. The sparkplug is still in there and I think thats the next step, but afraid this is worse then a misfire the way its acting. Any thoughts?

 

2006 F150 with the 5.4 V8 - Recently replaced all plugs and coilpacks; however, after a month I went to start the truck and its shaking like a tractor and I don't think its drivable. Ran a scan and came back with an P0303 code tried swapping out the coil for a new one and no improvement. The sparkplug is still in there and I think thats the next step, but afraid this is worse then a misfire the way its acting. Any thoughts?

 

New plug could be cracked during shipment or during install
Fuel leaking (injector)

Could be some other issues, but that's where I would start

 

Yeah, swap injectors with another cylinder to see what happens.

 

Help! 2003 f150 4.6 cc (225,000 mi.) just ran a scan and it reads cylinder 5 misfire detected. Do I pull the plug and check it out (a first for me) or is there something else to try. Haynes repair manual warns me about pulling the plugs myself and TSB 08-7-6 warns about breaking an electrode on the plug and using a special lubricant when reinstalling. Is there some other check to run before pulling the plugs?

 

Nothing to worry about with the 2003. Replace the plug and torque it to 28 ft. lbs. Failure to torque it enough could lead to plug blowout. It was the 04 and later 3 valve motors that had the plugs that break when removing.

 

Unless you know for a fact that the plugs have been changed in the last 50k miles, replace them all. Use only Motorcraft plugs and torque them to 28 ft/lb.

 

Thanks for the help on the spark plug but it turned out to be the coil, I then got a new code for the catalytic converter but found a loose wire on the exhaust pipe sensor. Fixed that code with a good wire splice and now I have a 403 sensor A problem. I took off the EGR and cleaned it up (no deposits) reinstalled it and it came on again. Do I replace the EGR or should I look elsewhere first?

 

https://www.obd-codes.com/p0403