CEL code 32 Oxy sensor advice
 

First off I've searched so get fucked Nazi's.
I get a CEL every time I hit the freeway or go on a long continuous drive of more than about 20kl at or over 100kph I get code 32 which as far as I can ascertain is oxygen sensor but as soon as I turn the car off it goes away, I can drive around town all day and get nothing "94 WRX with a pod filter only" fuel economy is shit compared to my Liberty, so question is...........is it completely knackered or only playing up when I hit the highway? can it be cleaned? I've got a couple of old ones laying around but have no idea what model Subaru's they are off, provided the plug is the same would it be safe to chuck one in to try it?
That's all, thanks for any advice :)

Best bet replace with a new one to be sure. That's what i would do if it was my own car. The O2 can explain why you have shit fuel economy.

Yeah may have to, the spare ones I have are rooted.