could that also be just after driving off after the car has been started first thing in the morning? idles fine but 100m down the road the thing carries on for 5 seconds and goes fine again

Hmmmm i might look into this too. My car possesses both poor economy (bout 20l/100km on gas, not much better on petrol), and idles particularly rough on start up. Bought the car with 180k on the clock so it could be worth replacing.

replaced my O2 sensor tonight managed to get one for $70 for a NGK brand at motor spares ACT around 20 bucks cheaper than repco. hopefully next time i fill the tank it will last a bit longer. it did have a funny clour almost a bit rusty probaly due to my leaky head gasket that i have done a temp fix with chem i weld. which i am hoping will last a few more months till i can get it fixed.
regards

EBMontTom
hey dude sound like you may have a leaky head gasket if it runs rough at start up. does it mostly occur after the car has sat for long periods eg overnight.
regards