Inexpensive universal catalytic converters?

I'm building a replacement motor up for my trucklet. It will be on standalone and running closed loop. So why not throw a catalytic converter in a car that never had one. 

So looking at Amazon and ebay I see a ton of suspiciously cheap, hilariously brand named import units.  They are bafflingly spec'ed on vehicle weight as well.

Question is. Do they work at all? Am I better off spending 3 times as much for a Walker or Magnaflow branded one or will a Waterwich/Mayasaf/Autosaver88/LOLfitting actually function? 

I know they won't work as well as an expensive OEM emissions control device. This vehicle does not have to pass any emissions tests and never had a cat from the factory. My reasons for wanting one are that in my opinion,  engines tend to sound better with them (less raspberry noises) and well..... I like breathing around my cars. 

Based on the name, I would go with LOLFitting .

I think the question is if the ridiculously named cats are being made in the same factories to the same spec as the brandname ones, or if they aren't. Might be worth spending a little extra on something not off Aliexpress.

Yeah it is in the running based on name alone

So yea, in catalysts, you get what you pay for- mostly in terms of precious metals on the surface.

If I were you (and it's possible at some point on my Alfa, but I have some other stuff), I would try to find a cheap aftermarket one that does have an EO with it that makes it approved for aftermarket installation.  While few of those would last long for an OBD monitor, since you are adding one where there was not one before, it would work quite well.  They all have paperwork that they actually work, so you know there is at least *some* metal on them.

This would be a vote for any major US parts supplier with a generic replacement- Walker, Magnaflow, etc.

BoxheadTim said:

Based on the name, I would go with LOLFitting .

I think the question is if the ridiculously named cats are being made in the same factories to the same spec as the brandname ones, or if they aren't. Might be worth spending a little extra on something not off Aliexpress.

You should be paying for two things- the cost of certification and the metal on the surface.  Since for most parts suppliers, the former has been paid for many times over by now, the latter is the big cost.  And you can't cheat around that, especially now when platinum, palladium, and rhodium are REALLY expensive.

In reply to Trent :

Dang, I hadn't realised that you were serious about that name.

I’ve had good luck with Magnaflow cats in the past – they definitely work.  My turbocharged escort running on megasquirt passed state tailpipe tests for years with a 3” magnaflow unit.  I can’t speak to the off brands at all.

In reply to therieldeal :

Good to know. Was that a metal or ceramic substrate cat?

I put one of these on my Conquest last year, just wanting something cheap to knock out the catless stink: https://www.ebay.com/itm/234120927570

It definitely worked. Price has gone up $30 since last year, though.

I bought a cheap one for a Honda to get me by and diagnose an issue, the internals of the cat started to separate within a few months.

For my Integra, I bought a GESI cat that I plan on putting in when I get the new motor setup in and looks to be higher quality. 

alfadriver said:

So yea, in catalysts, you get what you pay for- mostly in terms of precious metals on the surface.

If I were you (and it's possible at some point on my Alfa, but I have some other stuff), I would try to find a cheap aftermarket one that does have an EO with it that makes it approved for aftermarket installation.  While few of those would last long for an OBD monitor, since you are adding one where there was not one before, it would work quite well.  They all have paperwork that they actually work, so you know there is at least *some* metal on them.

This would be a vote for any major US parts supplier with a generic replacement- Walker, Magnaflow, etc.

Do you think it's worth adding a cat with a home calibrated closed loop system?  My initial thought is that it's not going to do much in the first place and that without the tools and knowledge to crate a cat friendly calibration it's not likely to last long.  Am I being to cynical?  Are cats less fragile than I think they are?

In reply to APEowner :

I do.  And making the engine drive well and not hesitate will make it happen.  If you target stoichiometry, or lambda/gamma of 1 when you are mostly driving, then just getting the a/f targeted there AND having the transients good enough that it does not hesitate (either rich or lean) it will work pretty darned well.

The perturbations are actually good for conversion, but the degree of control most would calibrate in would be good enough.   Not perfect, but with WB sensors doing the hard work, it would work pretty darned well.

Cats are not all that fragile, actually, unless you make them face misfires- then they will destroy themselves pretty quickly.  Going rich (W/O Misfires) is not a bad thing- keeps temps down and the life up- and honesty, the emissions are shockingly not that bad, too.  

So- target stoich most of the time, power enrichment is fine (down to 10:1 even), make a/f smooth enough to not hesitate, ELIMINATE MISFIRES, and emissions will be pretty darned good.  Very worth adding a catalyst.

Thank you for all this info Alfa!

Trent said:

Yeah it is in the running based on name alone

It's a LOLcat. Brilliant marketing, if nothing else.

alfadriver said:

In reply to APEowner :

I do.  And making the engine drive well and not hesitate will make it happen.  If you target stoichiometry, or lambda/gamma of 1 when you are mostly driving, then just getting the a/f targeted there AND having the transients good enough that it does not hesitate (either rich or lean) it will work pretty darned well.

The perturbations are actually good for conversion, but the degree of control most would calibrate in would be good enough.   Not perfect, but with WB sensors doing the hard work, it would work pretty darned well.

Cats are not all that fragile, actually, unless you make them face misfires- then they will destroy themselves pretty quickly.  Going rich (W/O Misfires) is not a bad thing- keeps temps down and the life up- and honesty, the emissions are shockingly not that bad, too.  

So- target stoich most of the time, power enrichment is fine (down to 10:1 even), make a/f smooth enough to not hesitate, ELIMINATE MISFIRES, and emissions will be pretty darned good.  Very worth adding a catalyst.

I just realized that while Trent clearly said closed loop and I even typed that in my question my brain was thinking open loop.  I'm not sure I would have asked the question if I'd realized that sooner.  Regardless, I appreciate your input and expertise.  Thank you.

Glad to help.  I do always think of feedback given the pretty low cost of WB set ups these days.