Aftermarket catalytic converter lifespan?

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Jan 26, 2019
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Israel
I intend to add an aftermarket catalytic converter to my car, after its was stolen, and I do not intend to buy the original because it is very expensive, Which works to divert toxic gases in the exhaust of the car into less poisonous gases. However, I read that aftermarket catalytic converters have a shorter lifespan than the original ones, and in my opinion as a logical result, the aftermarket catalytic converters should have a longer lifespan because they do not purify any of these gases and it is just a mufflers, and that the temperature inside it is lower than in the original catalytic converters, because there are no precious metals in its components, am I right?
 
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Sounds like you've got some misconceptions about cats..

Aftermarket works like factory, but don't tend to last as long and may give somewhat higher emissions too, unless you buy one that (at least in the US, is "CARB" approved) - you get what you pay for.
 
Sounds like you've got some misconceptions about cats..

Aftermarket works like factory, but don't tend to last as long and may give somewhat higher emissions too, unless you buy one that (at least in the US, is "CARB" approved) - you get what you pay for.
I don’t care about emissions quality, I only care about the engine sound, and I intend to use oxygen sensor spacer to get ride of the code p0420, I found a catalytic converters under $50 without precious metals
 
I don’t care about emissions quality, I only care about the engine sound, and I intend to use oxygen sensor spacer to get ride of the code p0420, I found a catalytic converters under $50 without precious metals
Then those are not catalytic convertors. I'm not sure what your question is? Lasting longer? Do you mean rusting out? There is no way for us to know. If stainless is an option, buy that.
 
I see what you're saying and if your locale doesn't have an emissions inspection, then go for it.

Getting back to your initial post, you've missed the mark - the aftermarket converters attempt to do the same thing as the OEM cats, but don't last as long due to not having as much precious metals in them.

If you're looking at achieving a particular sound, then maybe add a resonator or similar in place of the cat?
 
You're basically bypassing the catalytic converter. It should last until it too rots (many factors are involved to determine life span) unless it's stainless steel.
 
However, I read that aftermarket catalytic converters have a shorter lifespan than the original ones, and in my opinion as a logical result, the aftermarket catalytic converters should have a longer lifespan because they do not purify any of these gases and it is just a mufflers, and that the temperature inside it is lower than in the original catalytic converters, because there are no precious metals in its components, am I right?
Huh? Im not sure I understand your logic.

I experienced based upon dyno emissions tests, that an aftermarket converter works/converts about as well new as a failing OE converter performs with 10+ years and >100k miles. Lived this with my 318i which had no egr and high NOx until I went with an oe replacement which reduced the emission by 1000ppm or more.

But I’m not getting your logic on longevity. You mean conversion efficiency? If so likely not. The emissions are what they are. Catalysts degrade in a number of ways, and a much lighter/weaker washcoat will mean higher catalyst temperature and less active material able to “fill in”.

If you truly don’t care about emissions, just install a muffler or pipe. I think it’s an irresponsible idea, but if it’s allowed then it is an option. Better would be to fix the issues that caused the converter to fail, then use one that has a CARB or similar pedigree so the amount of washcoat is higher.
 
Yes you can buy a universal cat on ebay for a hair under $50.

They do not have the same amount of precious metals as OE.

They're legal to install in about 46 states. Cali, Maine, and a couple others require OE or equivalent.

They do have to meet EPA regs which are looser than those for OE cats. But the EPA is cool (for once) and understands that an aftermarket replacement is probably going on some beater that's near its end of life.

There is an EPA warranty-- 5 year, 50k miles. IDK how this applies in Israel, but if you can find something that meets US specs there may be a little bit of quality.

I have had an OBD-II car that flunked the worn out OE cat via OBD. It passed with an aftermarket cat, no spacers on the o2 sensors or other shenanigans.

It is my understanding that cats often fail by having carbon cover the precious metals in the honeycomb, preventing them from effectively touching exhaust gases. By this logic an aftermarket cat with less in it would fail faster, particularly if the engine isn't perfectly healthy and sends more carbon down the system.
 
Then those are not catalytic convertors. I'm not sure what your question is? Lasting longer? Do you mean rusting out? There is no way for us to know. If stainless is an option, buy that.
Yes you can buy a universal cat on ebay for a hair under $50.

They do not have the same amount of precious metals as OE.

They're legal to install in about 46 states. Cali, Maine, and a couple others require OE or equivalent.

They do have to meet EPA regs which are looser than those for OE cats. But the EPA is cool (for once) and understands that an aftermarket replacement is probably going on some beater that's near its end of life.

There is an EPA warranty-- 5 year, 50k miles. IDK how this applies in Israel, but if you can find something that meets US specs there may be a little bit of quality.

I have had an OBD-II car that flunked the worn out OE cat via OBD. It passed with an aftermarket cat, no spacers on the o2 sensors or other shenanigans.

It is my understanding that cats often fail by having carbon cover the precious metals in the honeycomb, preventing them from effectively touching exhaust gases. By this logic an aftermarket cat with less in it would fail faster, particularly if the engine isn't perfectly healthy and sends more carbon down the system.
Yes you can buy a universal cat on ebay for a hair under $50.

They do not have the same amount of precious metals as OE.

They're legal to install in about 46 states. Cali, Maine, and a couple others require OE or equivalent.

They do have to meet EPA regs which are looser than those for OE cats. But the EPA is cool (for once) and understands that an aftermarket replacement is probably going on some beater that's near its end of life.

There is an EPA warranty-- 5 year, 50k miles. IDK how this applies in Israel, but if you can find something that meets US specs there may be a little bit of quality.

I have had an OBD-II car that flunked the worn out OE cat via OBD. It passed with an aftermarket cat, no spacers on the o2 sensors or other shenanigans.

It is my understanding that cats often fail by having carbon cover the precious metals in the honeycomb, preventing them from effectively touching exhaust gases. By this logic an aftermarket cat with less in it would fail faster, particularly if the engine isn't perfectly healthy and sends more carbon down the system.
What I meant by the longevity of the catalytic converter is the period / distance that can be used before its cells become clogged, which leads to poor performance of the car
 
I don’t care about emissions quality, .....

You should care about emissions. Buy a HJS cat if available for your application.
Excellent quality, will last virtually forever and retain both factory spec emissions
and performance. Still affordable at least in Europe. If you want more power (and
the car in question is worth it) get a HJS metallic cat.
However you didn't provide ANY data at all necessary for giving specific answers.
.
 
Have a Magnaflow Hi- Flow cat on my Silverado that's been on the truck for the last 20 yrs, still passes the Cal smog checks.
 
If your engine wasn’t burning oil with the original, you should be able to get a few years out of a replacement. How strict are emissions regulations in Israel? Tailpipe “sniffer” test or not?
 
It is my understanding that cats often fail by having carbon cover the precious metals in the honeycomb, preventing them from effectively touching exhaust gases. By this logic an aftermarket cat with less in it would fail faster, particularly if the engine isn't perfectly healthy and sends more carbon down the system.
No, carbon doesn't impact the precious metals much. It's heavy metals in the exhaust gasses, like lead, sulphur, Zinc. You know, all the metal compunds found in motor oil (and in the case of lead, it USED to be in gasoline) that help prevent wear. However, if your car burns a LOT of oil it will "poison" the CAT faster.
Cats can also fall apart inside due to physical damage, like hard bumps.
 
The secondary oxygen sensor can generate a check engine light if there is insufficient catalytic action. One method to address this check engine light involves installing a small amount of catalytic converter core material in a section of pipe that feeds the downstream O2 sensor. The problem with such a design is the small catalyst does not have exhaust flow over it, and therefore won't heat up properly under all conditions. It's also very short, so there is not enough time for it to do the job.

Below is an example of a product that may or may not eliminate the CEL. Don't expect perfection with this approach. One really needs exhaust flow and something like 80mm of surface length.

Note: In the end, a very high quality metal matrix high flow cat will not restrict exhaust flow and will be effective enough to prevent a CEL. Seems crazy to spend $200 for an effective O2 fooler, when a 300 cell metal matrix can can be found for $225

Here is a metal matrix cat at the end of the pipe, glowing red:

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Yes you can buy a universal cat on ebay for a hair under $50.

They do not have the same amount of precious metals as OE.

They're legal to install in about 46 states. Cali, Maine, and a couple others require OE or equivalent.

They do have to meet EPA regs which are looser than those for OE cats. But the EPA is cool (for once) and understands that an aftermarket replacement is probably going on some beater that's near its end of life.

There is an EPA warranty-- 5 year, 50k miles. IDK how this applies in Israel, but if you can find something that meets US specs there may be a little bit of quality.

EPA warranty is 2 years/25k for catalytic performance, 5 years/50k for structural integrity

Only California requires a 5 year warranty on catalytic performance.
 
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