My check engine light came on for the second time today. I have only had the car for a few weeks. Took it to dealer after the first time, which was just a few days ago, and they said it was a misfire on cylinder #3, code P0303. They did an activation test on each cylinder and all was normal so they just cleared the code. Will probably take it back to dealer this week to have them see why the light is on again now. Needless to say, I'm getting concerned. Anyone else experience this? I hope it doesn't end up being a huge problem because otherwise, I love the car.

 

I wouldn't be too concerned at this point. I'm sure they will sort it out. Do you notice a change in engine performance when this happens? A misfire, especially in a four-cylinder car, will be very noticeable with the engine running rough and being way down on power. If it only lasted a second it wouldn't be as noticeable.

 

I didn't notice any difference so it must've been short-lived. I dropped it off at the dealership this morning. The engine light actually went off by itself yesterday. Dealer service dept said if it was a loose gas cap, it will reset itself if it no longer detects a problem. I told them to pull off the code history anyway because I want to know what it was. The car has also pulled to the left ever since I got it and I'm getting that fixed too. Apparantly this is a known/common issue and Hyundai has a new part to fix it. Can't remember exactly what the new part was. I'll post an update when I get the car back.

 

That's good. I hope they take care of everything to your satisfaction.

 

Got car back from dealer. The code was the same as before, misfire on cylinder 3. Hyundai advised them to update the ECU software so that's what they did. Everything seems fine for now, time will tell.

 

Doh! Drove car from Charlotte to Atlanta yesterday, and after sitting for about 5 hours in Atlanta, I cranked it up and the check engine light came on again. This time, the cylinder misfire lasted longer as it idled very rough for about 10 seconds. The previous two times I didn't even notice anything unusual. This will be third time back to service department for the same problem - very disappointed. Starting to wonder about whether I have a lemon here.

 

I have a 2011 Sonata SE 2.0T. It has 3600 miles on it now. I've got a constant check engine light with a constant, sporadic misfire. It started Saturday. I took it in to a dealer. Code was P0302, misfire in cylinder #2. There was another code, but they thought it was a result of the first. They said all injectors activated fine. They would have to call the "Tech Line" on Monday. I'm taking it to the dealer I bought it from on Monday to leave with them for the day. Hopefully its something they can resolve.

 

Dealer has had car since Thursday. The car actually misfired when they cranked it so they were able to repeat the problem. They are keeping it another day to crank it cold again (mine only happens when car is cranked cold).

They said they swapped the ignition coil wires to see if the problem follows the wire or if its something else. I know just a little about cars and this didn't make total sense to me because I thought that the order that the cylinders fire in is important and it seems moving the spark plug wires would not work very well. I assume that is the same thing as ignition coil wires but maybe they are referring to wires between the distributor and ignition coil? Still, wouldn't it have the same effect? I don't know. I didn't question them, but hopefully they weren't feeding me some BS. I would like to know how many other turbos have been recorded with this problem in Hyundai's database. I'll post and update on this saga when something changes.

BTW, the fuel door on my loaner Sonata would not open today. Luckily I was able to get to the dealer (on fumes!) where one of the mechanics pried it open while I pushed the button. I have no confidence in the Hyundai brand right now.

 

The dealership has had my car all week. They are waiting on an injector to be delivered but the snow is slowing the shipment down. They noticed the tip of the spark plug for cylinder #2 was fouled, they also said the injector wasn't cycling properly.

Once the injector gets delivered and installed, along with a new plug, we'll see where things are.

 

The Hyundai dealership replaced the #2 injector, the plug, and the high pressure rail. There are no more codes or check engine light. Car seems to drive fine. I'll up date if there are any changes.