P0304 Code after takeoff?

2011 HONDA ODYSSEY

205,600 MILES • 3.5L • V6 • 2WD • AUTOMATIC

ETERNALARIANNE

MEMBER
240 POSTS

I went to takeoff at a stop sign to beat traffic and squealed tires a bit. Then the engine shuddered and CEL started flashing. It ran rough after that until I got home less than a mile away. Turned it off and back on and CEL did not come on. I checked the code, and it was P0304 misfire cylinder 4. These spark plugs were put on at the dealer around 10,000 miles ago. Is this anything to be concerned about since it just happened one time?

Feb 3, 2023 at 5:09 AM

STRAILER

✓ASE Certified Mechanic
54,832 POSTS

I would remove the #4 spark plug and check the porcelain housing for cracks, next I would replace the ignition coil which should fix the problem. here are the instructions so you can fix it yourself. Also, it should be known that a spark plug can be defective even though it looks okay. Here is the cylinder location as well.

This generic guide can help walk you through the steps:

https://www.2carpros.com/articles/how-to-change-spark-plugs

This guide can help as well:

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Check out the images (below). Please let us know what happens.
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Feb 3, 2023 at 12:07 PM

ETERNALARIANNE

MEMBER
240 POSTS

I drove it again later today and it was fine, no CEL or running rough. My neighbor who used to be a mechanic said sometimes when you gun it like I did too much fuel can enter one cylinder and "foul" the spark plug for a while, causing misfire. But he did mention if it continues to happen the plug or coil could be bad.

I'll try to pull the plug and check it this weekend and see how it looks.

Feb 3, 2023 at 12:43 PM

STRAILER

✓ASE Certified Mechanic
54,832 POSTS

Please do, the misfire will probably come back. Please let us know what you find.

Feb 4, 2023 at 10:55 AM