Oxygen Sensor Problems

VolvoManiac · Post by **VolvoManiac** » 31 Jul 2007, 20:33

I own a Volvo S80 car and I my car's performance is already declining, my main problem are the oxygen sensors I don't know when to replace them because it's been more than a year, I asked my friend about this one and advised me to get an emission check, and I like to ask if are there are any alternatives to check if I need to replace my oxygen sensors... Thanks in advance!

Post by **JRL** » 31 Jul 2007, 21:18

Your check engine light will tell you when to replace them.
Are you in a hurry, they're expensive?

F18 · Post by **F18** » 02 Aug 2007, 09:05

As JRL said there would be a CEL lit up on the dash if the O2 sensors are bad....you would be able to back up that with an OBDII Scan......Auto Zone could do it. The malfunction codes (if any) would indicate which sensor or part of a system is not working properly.

If you are experiencing a drop in MPG which I am experiencing on all my gasoline vehicles it could be due to the 10% Ethanol that is now in just about all gas....all grades nationally. Ethanol is an alcohol and all alcohol contains some water so it has much less punch than petroleum gasoline and screws up the fuel injector metering a little bit.

A quick edit and after thought.......we were told a while back by the BMW/Mini dealer to run a lower octane gasoline in our MINI. The lower Octane offsets the effects of the Ethanol. The Ethanol was effecting the high compression engine (about 10:1) by diluting the already highly retarded Premium Gasoline which has a higher Octane to suppress pre-ignition or compression ignition. It seemed to work!

Hope that helps....
Cheers,
Fred