Proactively replace catalytic converter due to age and wear?

[FireFox31]

What's the lifespan of a catalytic converter? Should I proactively replace an 18 year old, 270k mile catalytic converter while installing an expensive stainless Ferrita exhaust?

Four years ago, the cat gave me a P0420 "Catalyst Below Efficiency" code, I added a gallon of lacquer thinner to my gas, and the code went away. Last year, I found one spark plug fouling, likely passing unburnt fuel through the cat and exhaust. I wonder if these problems and age have worn out the cat, so it might damage this nice new exhaust.

Will an OEM cat purchased from a dealership be lower quality than the original one on my car? This was surely true of the OEM exhaust which rusted after only four years.

Thanks for your input.

[SuperHerman]

If it is working leave it alone. There is no magic formula for the life of a Volvo cat lifespan. Overall they have proven very robust. Failures are rare and usually caused by engine related issues. How many miles are on yours? Physically how is the exterior condition? Have you looked at the inner honeycomb structure and inspected its integrity? Have you looked up the cost of a new OEM Volvo cat? They are expensive. After market cats are affordable, but not all are legal in all 50 states. An OEM cat is superior in every way, but many times more expensive.

Are you installing the Ferrita exhaust yourself? I would install it in a manner that allowed the cat to replaced in the future in the least intrusive manner. I am not familiar with your specific model, but most Volvos have flanges on both ends of the cat assembly. Replacing it doesn't really disturb the rest of the system so were it me I would just put in the new system and leave the cat replacement for the future if ever.

What you don't want to happen is having the flange removed (if it has it) and a weld being used in replacement. This will complicate future repairs, but for a competent muffler shop or mechanic not really a big issue, just not ideal.

[oragex]

See above. The original one is really expensive and has lots of precious coating. Aftermarket are a joke - even if they don't throw CEL

I've read genuine replacement may simply not last more than aftermarket ones in terms of pipe. There was a guy in europe with a rotten genuine replacement exhaust pipe after 3 years

[Rattnalle]

The replacement pipes aren't the same as the originals. They don't even look the same when new since they're shipped in parts.

Regarding the cat at least with European fuel standards, probably equivalent to not driving on the cheapest option and well known chains in your end, they don't have a life span as long as the car doesn't brake down and kill it with a lot of oil for example. That or only driving very short trips so that it's never allowed to operate at temperature for a while. They usually last the life of the car even if that is 500' km or more.

[FireFox31]

What you don't want to happen is having the flange removed (if it has it) and a weld being used in replacement.

This is the heart of my problem. My cat pipe flange was removed - it's a long, painful story. The Ferrita exhaust will need its flange cut off to be welded to the cat. Before I make that drastic alteration, I'm evaluating if I should replace my cat, giving me back its flange, keeping all the parts intact.

Since you guys are confident that the original cat is robust, I'll leave it and have the Ferrita welded to it. I never could get that flange to seal perfectly, so welding is strictly better.

[E Showell]

If you do happen to scrap the original CAT at some future date, ask the installer for it back and take it to a scrapper -- I got somewhere on the order of $70 for mine due to precious metals content. Tuck that away. Most people don't consider it.