Volvo: 1999 volvo check engine lite, oxygen sensors, heating elements

Question
just got 2 new oxygen sensors -very expensive. But check engine lite is still on. Now the shop is saying it might have something to do with the ignition system. It is not heating up the sensors. Does that make sense. Can't get a NY inspection with a check engine lite on! We don't have all interior lites working-would that be relevant? Thanks - you have helped us before.

Answer
Kathy Rich,
There are heating elements in the H02S that would require power to them. Maybe the power to the heating elements has been cut off. I am not sure if the interior lights have something to do with it or not. Maybe the fuse for the lights is also for the heating elements.
Yes the exhaust heats up te H02S but they have a heating element to heat them quickly and keep them at a certain tempature. That make them more efficient.