Gday guys,

MY 98 TF magna is using a bit more fuel than normal. About 6 months ago it would get around 11-12L/100km around city and then 9L/100km on highway.

Now its using around 15L/100km.

The Air filter is near new, oil was changed with filter 1000km ago.

Only thing that hasnt been replaced in the O2 sensor. The car has done 203,XXXkm. Would this cause such a sharp sudden rise? Also it doesn't have any error codes from ECU.

Cheers
Matt

If the o2 sensor is the original, it's almost a certainty that it's past it's use by date. Other things to look at are tyre pressures (~38-40psi is ideal), wheel alignment, PCV valve (general cleanliness), ignition system condition (plugs, leads, distributor rotor and cap), injectors. There's so many things that can cause poor economy.

Yes o2 can cause this, definitely change it, & it will not generate any error codes.