Houllier said: "We are good at creating chances but we really have to start finishing them off now. It is down to us to start converting them.
"If you look at our record on shots on goal we are probably top of the league. We have created more chances than any other side.
"And yet we are nowhere near in terms of goals scored. This is an area that has to change because fourth place is in our hands now and we have to grasp it."