850 Wagon, Check engine light?

Can a bad muffler cause the check engine light in my '96 850 wagon to
come on?

I had noticed the car was getting a little louder and then the check
engine light came on. When I took the car for an oil change my Volvo
garage said that there were two codes for the o2 sensor.

They quoted me about $250 for the muffler and about $200 for the sensor.

What I'm wondering is if there is a hole/crack in the muffler, could
that create a back draft or something that made the computer say that
the o2 sensor was bad?

-Atif

 

It is probably coincidental that the muffler and O2 sensor are going bad
at about the same time.

John

 

O.K. thanks the input.

 

It is certainly possible, especially if the sensor identified is the #2
sensor, the one after the converter. It makes sense to me to have the
muffler work done and then see if the O2 sensor codes go away. My hunch is
that they will, but that's only a hunch. If the codes point to the #1
sensor, the one before the converter, it is less likely.

Mike

 

Mike, on the receipt under comments it said something like "error code
o2 #2"

I didn't know there were two o2 sensors. It has been a few days and the
check engine light has NOT come back on yet... I think I'll follow your
advice, have the muffler done before having the sensor done, especially
if the check engine light doesn't come on right away. I assume if the
sensor was really really bad, then it would come on pretty quickly.

Thanks,
-Atif

 

Sounds good to me. The front O2 sensor provides the feedback to adjust the
mixture, while the rear one just monitors the output of the catalytic
converter to see if the whole system is working right - particularly the
converter. It doesn't take much air on that one to convince it something is
wrong. The second sensors were mandated by the US OBDII standard in 1996,
but I imagine other countries required them earlier than that.

Mike