1998 safari Oxygen Sensor question

Check engine lioght came on-took to dealer they said that its the Catlyst converter error and it needs to be replaced. I'll buy that since it has 115,000 miles on it and it couild go any time. But they said that there are 3 o2 sensors also that need to come out to replace the converter. That does not sound right to me. The sensors should be after the manifold, one on each side and another after the converter or something.

Does anyone know if there is a sensor "on" the converter? I feel like I'm being ripped off by the dealer. The van is at the dealer so I can't take a look for myself.

There is one EGO sensor in either exhaust pipe just behind the outlets of the exhaust manifolds. The two manifolds are routed through a "Y" pipe and converge at the inlet of the single catalytic converter. There is a third sensor at outlet of the converter that checks the efficiency of the converter itself. This sensor is actually mounted in the rear exhaust pipe attached to the converter about halfway between the converter case and the the outlet flange. Unfortunately, the two exhaust pipes, "Y" pipe, converter, and exhaust pipe after the converter are welded as a one-piece assembly. You get the whole section from the exhaust manifolds to the inlet of the muffler as "catalytic converter" instead of individual pieces.

The three sensors are mounted in thicker steel bungs which are welded into the pipes. The techs could possibly have difficulty removing the sensors since the pipes could be rusted to the point of the bungs simply twisting out of the pipes as the sensors are unscrewed. Regardless, with that mileage, if the two front sensors have not been changed and are original, they are probably due or overdue for replacement. The rear sensor is less critical, and could be reinstalled if it still worked - Unless it comes out with some pipe attached to it as previously mentioned.

Unfortunately, the two front sensors are electrically heated, and are about $60 apiece instead of the $25 you might expect for a "plain" oxygen sensor. Then again, at $3/gallon for fuel, the fuel savings alone could pay for the sensors in less than a couple years' driving.

I don't think they are "ripping you off," but they could perhaps try a little harder to get the sensors out. If they have evidence of weak sensors, however, they are probably doing you a favor in replacing them..

It's unfortunate that they couldn't find the time to explain that to you, and you had to go digging on the internet for an answer. I guess their service manager or service reps don't feel it's necessary to keep their customers informed. Take a photo or two when you return. It might be a quaint bit of trivia or memorabilia to have some day, since if they continue to operate in that manner, they should be out of business soon.