CEL for catalist issues
 

Hi Volvo Fans


This is my first post, I just joined the group today. It has been a while since I have posted on a forum. I use to be on Rennlist.


I have a 2000 S70 with an intermittent check engine light that goes back
8-10 months now. Lately it is on more than off. The fault code is for catalyst inefficiency. The engine passed the California smog test in Nov. 2013 with flying colors and at the time the CEL was off. I don't think the cat is bad and that it may be an oxygen sensor problem. There are no drivability issues and the car runs like it always has even with 220,000 miles on the clock. It burns
1 qt. of oil in about 2000 miles of driving. Any other areas beside the O2 sensors that may cause this kind of CEL fault?


This Volvo S70 is the best car I have ever owned... bought it in 2004 with 50,000 miles on it for $13,000. I think it has another 50,000 miles left in it.

You should be getting fault codes specifically for the o2 sensors if they are the issue?

How is the flexible section on the exhaust ? It tends to fail and can trigger a CEL

The exhaust system is sound. I don't want to replace the cat, besides I have 1.5 years before the next smog test. The intermittent CEL makes me think that the computer is doing a diagnostic test from the front and back of the cat and when it passes the light goes out. However the light has been on for several hundred miles now. Is 220,000 miles the most to be expected in a 2000 S70 GLT catalytic converter?

The CEL finally went out again after more than 500 miles. I'm still looking for someone who may have had these intermittent lights and what the cure may be.