I am geting occasional check engine light and have yet to read it off. Wonder if the formerly bad turbo could have messed them up. The one I removed was literally wet with oil from bad seals.

dick

It is entirely possible if you have enough oil back there. The oxygen sensor measures the difference of the oxygen content in the exhausts gas and the outside air. If it's sample is contaminated with excessive hydrocarbons from an oil leak you bet it can screw with it. In fact when you buy O2 sensors for your later model Volvos they come with an adapter harness that is there for that very reason.

mark

Mark:

Thanks for your reply. There really was no or only minimal external leakage. When I took off the turbo the exhaust portion was literally slick with oil. Car Also smoked badly. No more smoke, but light does come on.

dick

Dick,
Ok I see your point of concern now, your turbo was barfing oil through the exhaust then? If that was the case it is the same deal only worse now because the sensor is coated with a baked on layer of oil. If that is indeed the case then you are kind of screwed on that one and need a new sensor. I guess a guy could try cleaning it off but I would not get your hopes up on that one.

Mark

Thanks, Mark. It was barfing oil into the exhaust. Will pull them and look. It does smell a little rich which also directs me to sensor problems. Will report back, and thanks.

dick