Had car 4 years, 09 CDL , 44k miles, serviced up to date.
Cruising around 50- 60 mph Eml flashes and will turn solid after around 20 miles , codes are P0300, P0301 P0302 P0303 P0304. Clear all codes and they'll be back after 20-30 miles.
Car runs fine , I can't feel any sort of misfire, idles...