does cel mean valves need ajustmetn

P0300 is a generic misfire code. P0306: #6 cylinder is misfiring. I'd start with checking the spark plug and ignition coil at the #6 cylinder, however there are many things that could cause misfire code. Zee

i am making ssumption that you are saying p0300 THROUGH p0306. if this is not correct- go back to zeetech's answer. that being said.... 1. make sure the ignition is not at fault- unplug coils one at a time and see if idle changes. 2. make sure fuel is not the issue- this is normally done by adding external fuel and seeing if miss is corrected. 3. these being done, this code can be caused by the valves needing to be adjusted- this is normal maintenance on this model. hope this helps!!