Hi Kris, the most common fault for non starting and renaults best spare part seller is the crankshaft sensor (£25ish) 15 mins to fit yourself its located on the joint between the engine and gearbox at the top held in place with two bolts easy diy job as to the oxygen sensor not as easy diy job but if you get the part most exhaust outlets will fit it for you
nigel
October 2007