Hey everyone. Newbie to this forum. Hope I can get some help from you guys. Been a Volvo owner for over 25 years. Have owned over 30.
Posted a new thread (though an old problem) on the XC90 section.
Would appreciate some help with cat. converter problem on new (07) XC90.
Thanks
Paul

 

How many miles? Cat converter health is measured by the O2 sensors - namely by calculating the differential pre-post cat. Intake air leaks or similar can appear as O2 sensor issues so I'd start by looking at vacuum lines, intake air runners etc. Are your burning any oil or have abnormal fuel consumption or seem down on power? Any exhaust leaks? If that all looks good, you may want to measure the O2 sensor reading using an OBD2 reader with a live data option. After that it may turn about to be an O2 sensor or a failing cat. Unless you have a burn issue or super high miles, I'd suspect an exhaust leak (ie near the flex pipe) or a sensor on its way out.

 

Thanks for the input. The car has low miles, 79,000. Doesn't use any oil. However, I have since discovered that the previous owner modified the exhaust. He took the two pipes after the cats into one pipe and into a single outlet resonator, instead of two pipes into two outlets. The car is excessively loud also. In your opinion ,would reducing two pipes into one before the resonator make it louder? Could this be the readings I'm getting also? I'm getting a constant P0441 code now. The loudness is very annoying and discouraging; need to do something about it.