this happend while i was driving at a steady speed and then accelerating gradually not suddenly. what happend was the car sounded like a subaru from 2000-4000 rpm. and felt like it wasn't running that good.

i emptied the gas tank and put in gasoline after that the car ran better and the sound was gone. a friend of mine told me that maybe it was because of a dirty batch of fuel.

also i just changed the spark plugs and had the tension wires checked everything is normal.

need some help on what may be the problem is thanks!

 

You could of have a bad or leaking BOV causing whats called part throttle bucking. Check you BOV for leaks and also check that connections on it are secure and the vaccuum lines for cuts to the BOV also. Another thing did you get any CEL at this time?

 

no CEL light.