Random missfire

[Welder7018]

I have a random missfire on cylinder #1. It threw a code and check engine light came on for a few mins then went off hasnt came back on but shows code memory for missfire. And randomly shakes slightly at idle then goes away. Sometimes while driving too. Would a bad COP cause this?

 

[69Hcode]

Sounds like a bad COP. You should put vehicle info (year, engine size, etc) so you get better help.

 

[thenaaks]

COP could cause it. Swap the cop to another cylinder to see if the misfire code follows. That will confirm bad cop.

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[Welder7018]

Sorry its a 2003 Eddie 4x4 with the 5.4. And i will try that.

 

[Chris08LTD]

I had a random misfire on my 98 5.4. No constant CEL. The truck would hesitate on acceleration. Sometimes the CEL would flash but would go away. I replaced the plugs, coils, fuel filter, air filter, the vacuum line that goes behind the throttle body, vacuum line to the brake booster and cleaned the MAF. Needless to say I was so frustrated when none of the things I did solved the problem. I checked all the coil wires one day and found the number 8 coil wire was in bad shape. The wire was coming out of the sleeves creating a short in the circuit. I bought a new pigtail from Amazon, connected it and no more hesitation.

 

[Welder7018]

Its got a 24k mile 24 month warranty from the dealer so if it happens again they can mess with it lol.