I recently installed a fass 150 and I was fuel light was coming on and going out every now and then so I unplugged the big and small wire connectors to the fuel bowl winch its not getting used. now its coming on more. p0460 is the code that seems to match up to the problem. is it even a big deal... and my fuel gauge doesn't work either probably the sending unit.

 

I think it is actually because of the fuel level unit in the tank that you would get that code. It makes sense since you say the gauge does not work. The wires going to the filter would be for water in fuel and wouldnt cause what you are talking about.