Car has been sputtering or chugging of the line in first gear
I have a 2012 Sonata GL six speed manual with 122000km. For a little while now the car has been sputtering off the line in first gear, as if it's not getting enough gas, kind feels like it would if you tried to start in the wrong gear. It only starts to do it if the car has been driven a lot during the day, not on the first startup. I tried switching to premium gas, which helped a little, I replaced the spark plugs about 10000km ago, which also helped a little, but the problem has persisted. A couple of weeks ago I had the Major fuel system cleaning done, from Hyundai to try and fix the problem but it's still occurring. Any ideas? Fuel filter possibly?