code p0011 engine knocks replaced engine oil,filter,spark plugs flushed old oil

You can check to see if it has a Knock Sensor installed somewhere on the engine. It also could be too low of a grade of gas you're using. Does the knock get louder as your speed/RPM increases? Could be a piston rod or just lifter clatter. I'm not familiar with that OBDII code number. Those codes usually start at PO101 and go up from there.

http://engine-codes.com/p0011_kia.html This CODE can be caused by the lack of regular engine service (oil changes) low quality/incorrect oil/filter type... 'According to KIA'.! ... Have a 'mechanic' listen to the engine for noise evaluation!!