It's my dad's car a 2012 Hyundai Sonata GLS 2.4L GDI, yeah I know, I told him not to buy it. Anyway, so I don't work in a shop anymore, so I no longer have access service information or a good scan tool. It's got a hesitation when accelerating. Not all the time, and throttle position doesn't make a difference. It also misses at idle, again its intermittent. Sometimes as much as every 5 seconds, and sometimes it doesn't at all. Cold or warm doesn't matter either it's completely random. Coding for a p0302: cyl2 misfire. My dad did a tune-up on it, and put a coil on 2 before calling me. Made no difference. So when I got to it I swapped the plug from 2 to 1, and the coil from 2 to 3, just to double check, and see if the miss would follow it. It did not. Then I pulled the intake, and cleaned the injectors, and swapped 2 to 1, and yet again misfire stays on 2. Compression test was good, and the same across the board around 100 the first puff and 180 the 5th puff. I've done wiggle test everywhere I could think of, to see if I could get some kind of consistency of the miss, and nothing. Starting to think ECM, but without a scope I'm definitely gun shy to make that call. I'm just scratching my head here, wondering what to do next. Any insight here or a TSB pointing me in the right direction would be great, thanks for reading, I know it's long.

 

Take it to a dealer. Dad will pay.

Serving suggestion.

Or:

https://www.hyundai-forums.com/

https://www.hyundaiforum.com/forum/

There are more....

Some people here speak Hyundai, so you may get a better answer.

 

If your dad bought it new and it's still under 100,000 miles, it should be under warranty.