Was throwing the P0440 code. Refilled fuel and reset ecu by disconnecting batt. Code showed up again. Replaced gas cap with new cap. Code went away temporarily then popped up again. KJ drove fine with light on too frustrated to bother with it.. Was in a rush to work yesterday and needed gas. Put some cheap 711 89 low grade gas in a rush. Started KJ up after work last night and threw the P0441 code. KJ shakes lightly as if a cylinder is not firing properly or with full power.. Can cheap gas do this? Any suggestions? And anywhere where I can find a list of engine codes?