2008 Roush 427R runs great when the car is cold and runs decent when warm in cool temperatures, but after it warms up or air temp gets about 80 or so it spark knocks and hesitates badly and just lacks power from 2000 to 3000 rpm during acceleration. Any ideas? Oh and no codes at all
Has 80k on it, never have ran anything lower than 93 octane in it and have tried multiple different gas stations in case may have been bad. Already changed plugs, fuel filter and cleaned fuel injection but still does the same.