My Levin has been quite terrible lately, smashing 30l of fuel within 250 odd k's. The majority of driving is round town short trips though, which clearly doesnt help. I have no doubt the o2 sensor is poked, and I have a feeling the injectors are a bit leaky too.
Have some facelift injectors to put in, so will be interesting to see how much of a difference (if any) they make.