We did take it to the dealer as well as a reputable mechanic for Volvos. The dealer was vague and the other mechanic told us O2 sensors and converter. I want to know what caused the failure of the converter. Breather box?

Well a while back they told us about the engine seal (head gasket?). We changed the plugs when the car became sluggish at accelerating. That is when we noticed the fouled plugs. We had a slight leak last summer but have not had one since. My husband says he sees oil on the engine but none that leaks...

Well the code P0420 so that has something to do with the exhaust from what I have read. I also read that if you have a bad converter there are other issues. Since my car is running poorly, at high speeds, lack of acceleration, I know I have a problem. Also when replacing the spark plugs one was cove...

My husband usually goes to autozone and they read the codes for him. I do not have the codes...but on the list of issues was the catalytic converter as well as the engine seal.

We have an S60, 2003 with 106,000 miles on it. In the past 4 months we have spent quite a bit on it. We had the belts replaced when we heard a whistling type noise and it turned out to be something else (not sure what). We had to replace our radiator, and now we have been told that we have a bad cat...