Code P0304 only comes after idling

2006 DODGE RAM
125,000 MILES • 4.7L • V8 • 4WD • AUTOMATIC
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DEAN KOOPMAN
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Earlier this week my truck was throwing me a P0304 code. I assumed it was the spark plugs so I changed all of them. Reset it and it gave me the same code. Then replaced the coil pack for the fourth cylinder. Now it only throws the code if I’m idling longer than a few minutes. when it’s idling you can feel it shaking pretty good. I’ve looked at a couple of other forums and haven’t found any solid answers. any ideas?
May 9, 2021 at 8:56 PM
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ASEMASTER6371
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Good morning,

I would start with a compression test. You need to make sure there is sufficient compression for the cylinder to produce power.

https://www.2carpros.com/articles/how-to-test-engine-compression

Let me know the results.

Roy
May 10, 2021 at 7:29 AM