I am getting a strange sound when the engine gets just over halfway on the thermo and I took it into the dealer and they said its the catalytic converter braking down.

Is this covered under warranty?

 

all emmisions are covered for 100kmiles maybe more. you need to get the TVT ecu tune, because stock ecu leans out under load which is hard on cats.

 

cool, cheers for answering my question. what is a TVT ecu tune?

 

they will enrich the fuel mixture so you don't melt the cats

 

is this an expensive option? how would i have this fitted?

 

You dont NEED this tune but it would help is all. As far as I know this isnt an issue with these cars so just get it replaced and you should be fine.

 

Actually, it's 8 years/80,000 miles federal emmissions warranty for all cars sold in the US. My former Mazda Miata needed a new cat at 62,000 miles and it was 2 months shy of 8 years from the in-service date. Local Mazda dealer got it back to me within 24 hours, $0 out of my pocket.

 

the cats will get fried with the stock ecu tune, only if you run the engine under high loads. everyday commuting will not hurt them. it's only an issue if you drive the car hard.

 

I got the same problem. The car was one year old and the mileage was 15000km. Chrysler in france take it under warranty.
The noise was really bad but performance was the same

 

I have just spoken with the dealer and they will be replacing all 4 cats under warranty I am a happy bunny.