there is this o2 sensor tsb out there (http://www.finishlineperformance.com/pdf/cx7/bulletin/01-016-08-1879.pdf). I was wondering whether o2 sensor could be the cause of some of the poor mileage complaints. If one doesn't get any error code on the instrument panel, does that mean there is no o2 sensor issue? Reading the tsb doesn't really make it clear. It could be read to say that the crack can be there even before any MIL code.
