Subaru has been using rear O2 sensors since at least 1995. The problem is that he's reading the info wrong. In a "normal" Subaru you would have a front and rear sensor. On an OBDII SVX you'd have two fronts and one rear. On your SVX (pre-OBDII) you have two fronts and no rear. At any rate, your car needs both O2 sensors replaced. This is probably causing the rough idle that you mentioned in another post.


Dave