Rio5 misfire


#1

My 2011 Kia Rio5 is misfiring bad, especially at idle and low speeds. I took it in to a non-dealer mechanic (since I’m no longer under warranty) and no codes came up. They said coil #3 was arcing, so they went ahead and replaced it and the spark plug. When I drove it home the car was misfiring more than ever. It misfired a couple years ago and I had a coil replaced (#3?) and a couple months after that it did it again. I could took it to another dealer (both happened while under warranty) and they said the reason the coil went out before was because the spark plugs were bad and hadn’t been changed. So they replaced the #3 coil and spark plugs and it was fine until recently. I’m scheduled to take it to a kia dealer service dept. on friday, does this still seem like a coil issue? If not, what could it be?


#2

Could be a bad spark plug wire.

Edit: When a spark plug wire is on the way out, just pulling it off the plug or coil can make it much worse.