blackbeastdriver79

Hey guys, I've got a major problem I need some help or advice with. Got a 2007 with the 5.4 3v, just over 93000 on it. Got to that point where at around 40mph it started doing the shutter that felt like it was slipping in and out of gear. Everything I've read and seen said it's time for plugs. I did my homework (know about the dreaded plug removal). I bought the Lisle tool and the OTC tool when I got the plugs and the COPs, which were all Motorcraft OEM parts. Changed everything out last Friday, made sure everything was hooked up like it's supposed to be. Now it runs worse than before. Rough idle, feel the miss at all speeds. Check engine light is flashing, then goes to constant on then back to flashing. O'Reilly's code reader says P0304 misfire on cylinder 4. Pulled the plug back out, it still looks fine. Read same code again. Swapped COP from cylinder 4 to cylinder 1. Still throwing same code. Tried the battery relearn process and no improvement. I'm at a loss. Please help!!!

RLXXI

You probably cracked the ceramic insulator during install, very easy to do. Pull that plug back out and look at it very carefully, with a magnifying glass if you have to. You'll find a hairline crack.
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blackbeastdriver79

I'll check it again but it didn't look cracked. I reinstalled all of them with the OTC tool which seals and holds the top post and the ceramic shield in place. Even made sure my torque wrench was calibrated and torqued yo the recommended 25ftlbs.

mbrick

Agree with Rnlcomp, try moving both the COP + spring + plug to a different cylinder, to see if the misfire follows that pair.

Otherwise, not many options left that would tie it to that cylinder but let's discuss when you get there.

blackbeastdriver79

I will definitely try that when I get home. I work oilfields in west Texas and I'm out on a two week hitch. I appreciate y'alls help.