Honda recalled the fuel pump on my 2020 accord hybrid. Several days after the work was done, while driving, a “Danger Do Not Drive” message appeared and the engine shut down. Towed back to the dealership they attributed the cause to a “damaged O-ring and returned the vehicle. Several days later I got the P0420 code and returned it to the dealer. They informed me that the catalytic converter had failed. I argued that their botched repair caused the failure and they said that it was only coincidental that the catalytic converter failed at the same time. I didn’t believe them and did some research.

A improperly installed O-ring compromised the integrity of the fuel system which resulted in the A/F ratio running lean. Operating the vehicle under this condition the O2 cause excessive exhaust temperatures which in turn essentially melted the catalytic converter.

I’m considering taking the dealership to small claims court to have them replace the converter that I contend they damaged.

Do I have a strong case?

 

Lol,no.

Not at all.

 

Welcome to the 1990-2002 forum.

Check your warranty coverage, its stated in your owners manual.
Emissions are usually covered for 5 years.
Hybrids may have longer warranty to cover emissions components.
Emission controls are usually Federally mandated warranties.
Call Honda of America, you might be able to have the catalyst covered under goodwill if it's just out of warranty.

 

The answer is YES a lean A/F mixture can foul a catalytic converter and Germain Honda of Ann Arbor paid to have the out of warranty work done because one of their mechanics botched a recalled fuel pump replacement.

 

The answer is still no. What you wrote with regards to a lean AF mixture is factually incorrect.

They goodwilled it.

Not because they caused the damage, but for....well......goodwill.

 

 

It wasn’t goodwill by the dealership - I had to sue them in small claims court and I won!

 

Dont get me wrong, Im glad you won. Dealerships can be dicks.

But them replacing the cat isn't proof a lean condition caused damage. In small claims court, it doesn't take much to win.

Had the vehicle been running rich or misfiring, I can absolutely connect the dots to the cat being damaged.

Running lean however would cause negligible, if any, damage to the cat. There's no accelerant.

Ive served as a Subject Matter Expert for the State of California in automotive cases in front of commissioners(never went before a judge,the few case Ive done were settled before court)

Funny enough,one of the cases was for 6k worth of catalytic converter damage done to a Jaguar. The shop was going to lose. They put faulty injectors in engine and,they started leaking and caused the cats to overheat and melt.