Maxima vibrates while idling, check engine light flashing

[cnoble81]

My 04' Maxima started vibrating very noticeably while idling the other day, almost felt like it was about to stop running. I put it in neutral while idling, and the vibration wasn't as bad, but when I started driving again, the vibrations were more severe. The service engine light began flashing while all this was happening. I've since driven the car, and none of these issues occurred, but I'm concerned because the car has over 150,000 miles on it, and I have recently noticed I'm not getting the average mpg I once did. A few months ago I was getting 21-22 mpg, now it's down below 20. Any and all help/advice is greatly appreciated!

[Outkast]

A flashing SES light means you are having a misfire event. When that starts to happen you need to stop right away otherwie you could make the converters breakup. With that kind of mileage have you have the plugs replaced?

[cnoble81]

Thanks for the response. Since the last occurrence I wrote about, the car has operated just fine. I had the spark plugs checked and they were worn pretty bad, so I did have them replaced yesterday. I also put in a new air filter and had the MAF cleaned. Like I said, this vibration and flashing sensor happened about 4-5 days ago, and since then, I haven't noticed or seen any issues with it. I'm supposed to pick my car up today, and am hoping that the new plugs will fix my problems. Do you have any other suggestions? Thanks again.

[bigmonster_ak]

Is there any update to this post ? My car (2004 Nissan Maxima with 157k miles) is doing exactly what you described. Any insight or thoughts on this?

[NutriaforBreakfast]

Need to get codes detailing possible problems for later

[the converted]

My 03 maxima did the same thing when it was cold out. Turned out to be a bad coil and a new one fixed everything. If your car is giving you a code for a miss fire p0300 the last number will be the cylinder that the miss fire is on. I swapped a coil from another cylinder and the plug from another different cylinder. If the miss fire stays in the same place you either have bad wiring or an issue with the engine. Most likely it will follow the plug or the coil and whatever cylinder it ends up on will show you what was wrong.