Has anybody used aftermarket catalytic converter on a Honda?

Has anybody used aftermarket catalytic converter on a Honda?

We have a 2010 Accord V6 that has repeatedly thrown an 0420 code. Some Google-ing seems to indicate that it's probably more than just a sensor and I will most likely need a new a new cat.

I've only had to replace a catalytic converter one time in my life. It was more than 20 years ago, and also on a Honda. I bought an aftermarket unit (probably from Advance Auto), and the sulfur smell that came out of it was so awful that I removed and returned it (after my emission test), and just gutted the old one for the remainder of my time with the car.

So what's the state of the aftermarket catalytic converter world these days? Are they any good? Any preferred brands?

I've got a set of Walker cats on the Xterra.  They seem fine?  No weird noises, smells etc.  The magnaflows were 50% more and I wasn't sure they were 50% better.

I put a magnaflow bolt-in on my 94 Miata track car when I bought it in 2017 (maybe 18?) to pass emissions.  It went through two roller tests here in CT, one when new and one in 2020, both passed with flying colors.   I'm assuming it's still working since then, I've had no reason to suspect otherwise. 

That's with ~20k, about 8k of that on track..

So, to answer the question directly, no, but I have no reason to believe it wouldn't work..

I've used direct fit converters with no issue.  I wouldn't use a universal cat on anything.

Just make sure that all the welds are intact.  One of the ones I had to finish welding for the manufacturer was for a 1.7l Civic.

Of all of the converters I have replaced on Hondas, most were V6s.  They start to phone it in around the 200k mark, give or take.

I've used a bunch of them. I saw about a 10 percent warranty rate on the parts house brands. I always preferred magnaflow but didn't really see a lower failure rate with them. They are better than a universal but worse than an OE. 

Is that one of the VCM J series that has oil consumption issues? As in could this thing just be contaminated?

I'd drop some cataclean in it, then go beat on it mercilessly, if that didn't fix it, I'd probably put a defouler on the downstream o2 sensor. If I was going to put a cat on it, it'd likely be an OE.

In reply to Opti :

I'm not familiar with Cataclean, but I'll look into that as a potential first option, as the car is several states away right now. 

No help on the cat, but also check that there aren't any misfires related to the VCM (variable cylinder management).  I run a device that tunes it out on both of our J-series Honda V6s.  Don't want you to replace the cat only to potentially harm the new one.

The only aftermarket cat I've ever used was a Magnaflow, but that was on a '92 Mustang GT, so a wildly different application.  It passed the CT roller test at the time with flying colors.  Since the V6 is OBD2, you'd just need to have all the readiness checks be clear and no CEL (if it's registered in CT).

In reply to dj06482 (Forum Supporter) :

This car had that issue corrected under warranty. New rings and a reflash, so I don't even know if the cylinders are still deactivating. 
 

Car is registered in Maine, where they require a yearly inspection, though I don't know exactly what that entails. 

In reply to Woody (Forum Supportum) :

If it's setting a bank 1 converter fault, one COULD say that the piston ring issues helped the converter to its grave.

The rings only get replaced under warranty if the engine is fouling plugs in cylinders 1 through 4.  If it is 1,2, or 3 then only one bank of rings gets replaced. 

Either way, the vehicle will be misfiring, and then they first verify that misfires are caused by the plugs fouling.  If that is the case, THEN they open up the engine and replace the rings.

So you have misfires, which hurts converters, and oil consumption, which hurts converters.

I can also attest that the new rings have a LOT more spring tension than the old ones, the free gap is about double on the new ones.  So, less likely to stick, but also slightly less fuel economy.  And yes, when pulling the piston out of the misfiring cylinder, the ring gaps will be all lined up with each other just like they say happens to cause the problem.

Yes.

I used a Walker converter on my Civic with zero issues. The light went off and stayed off.

On my daughter's CRV (stolen converter) I used a mega cheapie from Amazon. 125 dollar Sum Flung Dung quality of imported stuff. The light stayed off almost a year then came on last week. Over the weekend she came over and I installed a spacer on the rear sensor to turn the light off. Her car is nearing its end of life under our care so I didn't want to spend any more money.