I am new to this so and need some help. I am experiencing power loss in my 2011 Hyundai Accent. It has 53,000 miles on it. My engine feels like it's stalling and the check engine light turns on. I ran the code and it says P0303 third cylinder misfiring. I swapped out the third cylinder coil with the first cylinder and changed out the spark plugs. I cleared the code and drove another 200 miles with no problems. The engine started experiencing power loss again and then the light came on again. When I checked it, it said it was the third cylinder again. Since I know it is not the coil or the spark plugs I am at a loss as to what it could be. Any help would be appreciated.

 

Spark plug wires possibly. Been through any water lately?

 

I think the 2011 is coil on plug so it doesn't act like older accents with wires etc. I would say pull the spark plugs and check number 3 vs the other plugs. It may show signs of something wrong with that injector or the plug itself can be screwy. Take a picture of them and post it here. People smarter than me might be able to "read" them for you.

 

It's 3 years old, is it not under warranty still?

 

Very true.. and even if its a second owner it would still have its powertrain warranty intact.