O/T Leagcy CEL CAT ECU
 

O/T Legacy 2.5 GT limited 90k miles

A friend of mine has a problem..........

The check engine light stays on. The dealer says it's the catalytic converter and a knock sensor. That's $650 for thje car. The car has an extended warranty to 100K but dealers says Cat is not covered.

At around 70k miles the ECU was replaced due to engine knocking. This was done on warranty.

Do you think a case could be made with SOA that the faulty ECU ruined the CAT? The dealer has agreed to 50/50 good will replacement based on this argument.

Bad cat
 

I would go along with this as a modern cat should last pretty much the life of a car. Really any cat should under normal circumstances. I thought for some reason that cats by law were warrantied for like 100k and 10 years or 120k for 10 years or something like that. Guess maybe it varies by states.

Thanks benebob. :)

If the engine has a strong knock, that is from toooo lean of a fuel burning engine? Correct? or can an engine knock if runs rich?

What is worse for the CAT? lean or rich?

Eng knock
 

Knock could be caused by just about any aliment. Too rich or too lean are both bad as the cat doesn't get the amount of bad stuff it is designed to. Too rich means extra gas entering. Leaving deposits. Too lean not enough gas. Has trouble maintaining proper temp to eat everything. Either way I would never suggest replacing a cat and not having a complete diagonstic of the car done to find out the cause of the dead cat. Granted, if I had a car with 200k and one went that's a different story.