So the 440 in my demon is acting funny. Just took it out for a spin the other day and it drove OK... I noticed at steady state driving down the road it sputters and spits, not sure what thats all about. It idles fine and it doesn't pop or sputter when accelerating just when steady state or slowing down. Also I noticed when i let off the gas to slow down a pretty good cloud of smoke started following me down the road, but went away when it came down to idle or back on the gas. I've read somewhere that that might be worn valve seals? Anyone got any advice?