What’s the deal with expensive cat converters?

[samkeir]

Hi there,

Seen some recent chatter on MX5/Exocet groups about selling cat cons for 400+, but ebay is selling some for 40-70. Are OEM Mazda converters highly sort after, making them more expensive?

Thanks

Sam

[phaeton]

The old ones have precious metals in them, not sure what the new ones have in, probably the same but a lot lower levels, need replacing every 2-3 years instead of each 20.

[samkeir]

Jan 1, 2021 17:05:31 GMT phaeton said:

The old ones have precious metals in them, not sure what the new ones have in, probably the same but a lot lower levels, need replacing every 2-3 years instead of each 20.

Ah I see, thanks for the response.

[einy]

OEM cats have to perform for the EPA mandated 80k miles, aftermarket cats are not held to the same standard, nor do they carry the same guarantee. Given this, the OEM cats have more precious metals in them vs. the average aftermarket cat that is not EPA certified (and does not carry the 80k mile performance warranty).

That said, $400 for an OEM Mazda cat is very reasonable, all things considered.

[techcraft]

Jan 1, 2021 14:14:18 GMT samkeir said:

Hi there,

Seen some recent chatter on MX5/Exocet groups about selling cat cons for 400+, but ebay is selling some for 40-70. Are OEM Mazda converters highly sort after, making them more expensive?

Thanks

Sam

like mentioned, since cats are made of precious metals, the more precious metals,
the more they actual can create the chemical reaction to clean exhaust gasses. as far as cheap cats go, they are not known to last very long. My friend did some dyno running on a 500hp supercharged engine and said only lost 5hp going with an hjs high flow car. $$$$

[phaeton]

I bought a cat from clickparts off ebay less than £40, failed IVA because of it, CO was 0.7 instead of 0.3, bought another from somebody else was over £100 emissions immediately dropped to 0.07, so if you swap out the cat careful what you buy.

[casesensitive]

And be careful to buy a reasonable quality one, there are lots of documented cases of DPFs (not quite the same) going on fire when they're subject to in-car cleaning process. The difference there might €1200 for an OEM one, €200 for aftermarket, and they look the same.