start cold and it is hard to idle, very very bad misfire
after warm it still misses but 80% of the time will idle oki and intermittant
whilst driving it wont rev freely and develops misfire
you can hear it slightly missing at idle when it is running oki
loss of power & acceleration
no eml codes
it has had inthe past po1514, po1515 but once cleared they didnt come back
p0300 is the only code that appears which means cylinder misfire
it has egr cheater with ported tb
it aint losing coolant and no oil either so i dont think the head is cracked