Today my car was running fine on my way to work. On the way home, it was hesitant to start. Then I noticed that when I came to a stop the car was vibrating and the RPM's dropped (didn't stall) the check engine light did come on. When I took off from the light, it was hesitating to go and low on power. I stopped by the Advance Auto store for them to read my CEL Code. It said that it was a misfire in cylinder 2 and it could either be a coil pack or spark plug. Which does it sound like? Also the car has 150,000 miles on it and is on the original spark plugs. I do plan on changing those. What should I try first?

 

The check engine light actually flashes when you step on the gas. Also, it feels like it shudders when driving.

 

Change the spark plugs first since they're pretty much 50k miles overdue, I would bet there is alot of carbon buildup on the spark plugs causing the misfire. The symptoms you're describing is a misfire.

 

Have a look in your Scheduled Maintenance Guide in the glove box and open it to the 30,000 mile or 36 month page. What does it say after "replace air filter"?

Apparently, these coils have more power than other brands like Honda and they do errode the plug tips. It's a miracle you got to 150K with original plugs. Take a photo of them for us please.