I had 2003 F-150 4x4 Crew Cab 5.4 engine scanned at Autozone because had a miss fire. Came up with this code P0303. I was told it is #3 cylinder. Purchased new coil and plug. I am wondering how difficult it is to replace. Any input will be greatly appreciated as I can not find a manual on this truck

 

Cylinder #3 is pretty easy to access. You should change all the plugs at the same time though. Cylinder #7 is a pain to remove the coil hold down screw.

 

I probably should. I just didn't know how difficult it is. Thanks for info!

 

It's not that difficult but it is time consuming. You need to have plenty of extensions, swivels, etc.. The coil hold down screws are 7mm. It is helpful to have a 7mm socket as well as a 7mm wrench. Most of them are fairly easy to remove but cylinder #7 is a real pain. The fuel pressure regulator blocks it. With some patience you'll get it off.

 

If you are due for a tune up this could really be the problem. Have had to change several of the coil packs that quit firing.
If the miss still accures, look to the coil pack.
Bob

 

Replaced parts and re-ran code test and now comes up with P0303 and P0352. Can you help with the new code? Thanks

 

I just wanted to thank everyone for helping me with my truck problems today. I have it back and running true thanks to your inputs. Great site!!