I have a i20 classic and intermittantly during warm up phase I get engine light flashing for few seconds when it warms up no issues. fault started 6 months ago and has had new spark plugs since and showed up a misfire cylinder 2 fault swapped cylinder 2 and 3 spark plugs clear faults , still happens still showing cylinder 2 misfire and random cylinder misfire faults , I always use shell fuel and even tried v+ still occurs i've also tried a fuel cleaner but still occurs its so intermittant but still very annoying. i have taken into a dealer but no help mainly due to the intermittant nature.
The vehicle has covered 29,000 miles and has only ever had genuine spark plugs fitted but as the misfire is still shown on cylinder 2 after swapping cylinder 3 and 2 spark plugs can't see how it could be them. It seems that when the engine reaches operating temp and goes into close loop faze there's never a problem. fault code P0300 random cylinder misfire and P0302 cylinder 2 misfire, i can never get the misfire to occur while looking at it always on warm up phase while driving vehicle which is very frustrating!!.