I am a newby in Volvo Forum, however, a Volvo lifer. I recently purchased a 2002 S80 non Turbo with 100K miles. All was well until of course the next day after I purchased the car. The check eng light came, catalytic codes came up. Rather than just assuming I need a new CAT Conv for $1500+, what might I check first, sensors, O2?

 

Check for vacuum leaks then the O2 sensor.

What were the codes that were stored?

 

Thanks, unfortunately I did not get the codes from my volvo mech. The car seems to run fine. However, every so often, it sputters a little in low idle. Hopefully this is a clue in the diagnosis. I'll have to get back to my mech on the code(s). All I was told was Cat Conv. I appreciate your help.

 

The cats very rarely go bad. I would check for vacuum leaks,check O2, and Mass Flow sensor before replacing the cat.

 

Thank you. I kind of thought this was the case. I will certainly follow your recommendation. Hopefully I can convince my mechanic to do as well. He's fair but I think hes a little old school (pre 2000 series, eg., 200s, 700s, 900s). Thanks again. Geoff

 

Also block the exhaust and listen for any leaks. Even a small leak before the O2 sensors can throw a converter code. Best done with 2 people and on a lift.

 

Thanks again. Will do.