Thanks for the responses guys.I've already given the engine new plugs and leads.How do you know if the oxygen sensor is stuffed.I have an autometer a/f gauge fitted and it doesn't seem to work properly until the car is warmed up a little,so i guess the oxygen sensor is working since the gauge gets its feed from the sensors ecu wire.If i get a engine tune-up done at say ultratune,it would probably be a waste,right? Where would i take my car to get the cam and exhaust timing checked and/or adjusted? I live out near windsor/richmond NSW