trentsteel

I have a 04 ltd banshee and i'm haveing a problem with it's running condition. it kicks over fine and has good compression but when it's running and i give it gas, there will be a sputter out of the pipes. everything is completely stock except for a k&n air filter, but it probally needs cleaning. anybody tell me what it could be? i replaced the plugs and put fresh super gas in it. any help will be appreciated - thanks