I’ve been driving my new Saab now for a couple of months now and it’s been great.

There is however one small little anoying thing.

CHECK ENGINE LIGHT

According to the reader it’s a p0420, code which basically means that the cat isn’t working at optimal capacity.

The thing is though that the car only has 40000 miles on it and it basically scored a 0 (litlle to no co2 at all) on the last emmisions test so I really don’t think it’s the cat that’s at fault.

What would be the next likley cause? Oxygen sensor?