My thanks to everyone who makes Brickboard the truly wonderful resource it is. I only recently stumbled upon this site and two days ago sought advice in evaluating a wagon that had failed some emissions tests. I appreciate very much the responses I received. After reading these, I did "just ask the guy why" and he was forthcoming with an answer -and a groan. The seller reported that his car had needed only a new gas cap(!) but that neither he nor the fellows at the dealership read this on the emissions report where it was explicitly stated. Instead, they replaced both the catalytic converter and the oxygen sensor. Yikes...