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IF you replaced cat converter(s), which brand did you buy?

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Discussion Starter #1 (Edited)
I'd like to start a dialog to discuss primary catalytic converter replacement options.

I'm now with many others with a 10+ year old truck with 120,000+ mi. facing a cat code (P0430 in my case) and it's cat converter replacement time. I've been researching all the P0420 and P0430 threads here such as this one: http://www.thenewx.org/forum/11-powertrain-driveline/12752-p0430-bad-catalytic-converter.html

Sounded like Paul-XYZ bought Eastern Catylitic and had codes return in 20k mi. Also saw a post by Robust saying he bought Walker and it had a bent bolt and bent flange which was an instant exhaust leak. Would like to know others experiences.

There is a lot of scattered info on here, and I'd like to create this thread to aggregate into centralized source of info for those in my situation.

I'd like to know what worked and didn't work.
-When did you replace? (xxx,xxx mi)?
-What brand?
-How well did it fit? ie was it bent wrong, missing bolts etc)
-How many miles since you replaced?
-Have any codes returned?
-Do you recommend, and any feedback?

Example made up feedback post:

JoeBlowXterraGuy123; said:
P0420

Replaced cat with Walker direct fit at 120k mi. One bolt was bent. Fitment was a total pain. Have had for 20k mi, no codes since.
So lets talk about the options out there guys!

Here's a cost breakdown for comparison of what I'm seeing:

No code has to be inserted here.

*Note: some include gaskets and bolts others require separate purchase
 

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Discussion Starter #2 (Edited)
For those curious what it looks like when you have a cat going bad. The following is an excerpt from the FSM:


DTC P0420, P0430 THREE WAY CATALYST FUNCTION
On Board Diagnosis Logic

The ECM monitors the switching frequency ratio of air fuel ratio (A/F) sensor 1 and heated oxygen sensor 2. A three way catalyst (manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2. As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase. When the frequency ratio of air fuel ratio (A/F) sensor 1 and heated oxygen sensor 2 approaches a specified limit value, the three way catalyst (manifold) malfunction is diagnosed.


This video shows my B2 O2 S2 sensor high switching frequency indicating low oxygen storage thus setting a code for cat converter efficiency below threshold. In this case bank 2 (P0430) If you watch the botom right (B2 O2S2) you will see it switching way low to high. Compare that to B1 O2S2 at the bottom left which is much more consisitant.

The typical average values should be about:
B1 O2S1 ~0.3V, B2 O2S1 ~0.6V
B1 O2S2 ~0.6-0.7V, B2 O2S2 ~0.6-0.7V

Heres the vid:

Before (bad fluctuating B2 O2 S2 voltage):


After (good steady B2 O2 S2 voltage):


Hopefully this will help others in their diagnosis and understanding of what the ECM is looking for to trigger a P0420 (Bank 1) or P0430 (Bank 2) Catalytic Converter Efficiency Below Threshold code.

FWIW, at the time of this "Before" video mine has reached the point it will set the code within 100-200 miles after clearing. In fact it set only 30 miles after I cleared it.

Something else to consider and examine: Look at your Long Term Fuel Trims. If you see one side is way low, this will indicate it is taking away fule on that side because it is running rich. And if way high its adding fuel because the enine is running lean. This indicates a problem other than just age that is causing the cat to fail. In my case both banks are the same and normal. Thus indicating the converter has simply began to fail and run out of oxygen storage. ymmv

-Jay
 

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As a California resident and owner of a 2005 Xterra with almost 123,000 miles, I am particularly interested in information regarding CARB-approved and 50-state replacement cats.
 

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Sorry no long term report or fitment info but I did buy a set of davico's I'm gonna throw on as soon as I have the time, my drivers side has gone bad,hope they work out. I bought a complete set but only need the drivers so I'll be selling the passenger side it looks to have been replaced at some time.
 

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. . . Can anyone else contribute?
@Surf and Snow:

I know this doesn't help your search for the best or most cost effective replacement cats for an Oregon vehicle, but here's what I found that applies to those of us in California and N.Y.:

OEM - CARB approved - 50 State legal (and of course the most expensive)

Walker - Not Legal for Sale or Use in CA (Walker oxygen sensors are CARB approved but not Walker catalytic converters)

Eastern - Not Legal for Sale or Use in CA & NY

Davico - Not Legal for Sale or Use in CA & NY

Bosal - Not Legal for Sale or Use in CA

Magnaflow - Not Legal for Sale or Use in CA

Evan Fischer - Not Legal for Sale or Use in CA & NY

A Google search for CARB-approved or California legal catalytic converters, also searches on AutoZone.com, OReillyauto.com, and NapaOnline.com, have all turned up nothing. Thus far the only California legal cats I can find are OEM.

Sometimes I feel like telling the Kalifornia smog nazis that they can kiss my exhaust. :|
 

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Discussion Starter #10
Thank you for the info to help others @Mr. Bills

California is always unreasonably restrictive on everything (even lawn mower gas cans). Here in Portland, OR I am subject to emissions testing requirements for vehicle registration every 2 years. Fortunately there is no visual inspection component. For pre-OBD2 (<1996) they get a sniff test, and for all 1996+ its just a scan. Monitors need to show as complete and no P codes to pass, so fortunately for me, all these aftermarket cats are viable. But your contribution is certainly helpful for all our CA and NY members.
 

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@Surf and Snow:

I know this doesn't help your search for the best or most cost effective replacement cats for an Oregon vehicle, but here's what I found that applies to those of us in California and N.Y.:

OEM - CARB approved - 50 State legal (and of course the most expensive)

Walker - Not Legal for Sale or Use in CA (Walker oxygen sensors are CARB approved but not Walker catalytic converters)

Eastern - Not Legal for Sale or Use in CA & NY

Davico - Not Legal for Sale or Use in CA & NY

Bosal - Not Legal for Sale or Use in CA

Magnaflow - Not Legal for Sale or Use in CA

Evan Fischer - Not Legal for Sale or Use in CA & NY

A Google search for CARB-approved or California legal catalytic converters, also searches on AutoZone.com, OReillyauto.com, and NapaOnline.com, have all turned up nothing. Thus far the only California legal cats I can find are OEM.|
I wonder.... if there really is a difference between any of the aftermarket cats and OEM? The only thing I can think of is that none of the manufacturers want to spend the money to get the CARB(age) certification for such a small market. I bet that if a CA resident went to AZ, bought cats and installed them, that the vehicle would pass emissions testing with no problems.
 

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Discussion Starter #12
I wonder.... if there really is a difference between any of the aftermarket cats and OEM? The only thing I can think of is that none of the manufacturers want to spend the money to get the CARB(age) certification for such a small market. I bet that if a CA resident went to AZ, bought cats and installed them, that the vehicle would pass emissions testing with no problems.
The aftermarket cats tend to be cheaper because they use less platinum and other precious metals than OEM, and tend to have less oxygen storage capacity. But yeah, it's mainly Rediculous CARB B.S.
 

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I used two Walker cats (passenger side) on my 2005 Frontier and 2006 Xterra. Both purchased from Amazon.

The one that went into the 2006 Xterra fit perfectly and a few thousand miles later, code hasn't returned.

The Walker installed on the 2005 did not fit well, I had to re-weld one of the studs because it was too crooked.

I also purchased a Bosal from Amazon for the driver side on my 2005 Frontier, it was a horrible fit too. The tube was too large on both inlet and outlet.


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The way I did it was to hollow out the primary cats and remove the secondaries. Then I had 2 high flows welded in behind the hollowed out primaries and got the rear o2 sensors relocated behind them. So far so good, but we'll have to see how it works long term. It's not been like that long enough to tell yet for sure if it's going to be a long lasting fix or not.
 

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I'm experiencing the same situation, in fact I just sat down to start researching when I saw this post.
I'm wondering if I buy an aftermarket cat will it still pass the ECM diagnostics because of the parameters set up at the factory?
I would hate to spend the time and money just to have to remove them and then buy an Oem cat.
My code is 420, will I need to change both cats or just one?
Has anyone tried the cat cleaning solutions with any luck?
I hate this crap since I also have the 1446 code and have changed out the valve with no luck, I don't want to spend $200 for a vapor canister to find out it's not the problem either.
Well I guess it's time to call the guy, I do almost all my own work, but a man's got to know his limitations!
 

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When I changed the one catalytic on my 2006 Xterra, the code went away and never came back. It's been a few thousand miles since.

On my 2005 Frontier, previous owner gutted all 4 cats. So I only replaced the front two, so the SES light would go away.

It's been about 1k miles and no SES light since.


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-When did you replace? (12/26/15 at about 98k miles)
-What brand? Walker
-How well did it fit? ie was it bent wrong, missing bolts etc) Fit great! bolted right up w/ no issues or leaks
-How many miles since you replaced? about 20k
-Have any codes returned? No
-Do you recommend, and any feedback? I used Walkers for the primaries, and straight pipes to delete the secondaries. Walkers fit great, no modifications needed, Amazon with free shipping..cheap. It's been almost a year and have thrown no codes.

*Edited, did not see the requested format before.
 

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-When did you replace? (4-8-15 at about 118k miles)
-What brand? Walker
-How well did it fit? ie was it bent wrong, missing bolts etc) Fit great! bolted right up w/ no issues or leaks
-How many miles since you replaced? about 7K
-Have any codes returned? NOPE
-Do you recommend, and any feedback? I don't drive it much, I mean I've only put 7k miles on it in 18mths. The hardest part was getting the old ones out. reinstallation was very easy. And it passed emissions last month so I'm good for another 2 years.

 
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-When did you replace? Oct 2016
-What brand? Walker
-How well did it fit? ie was it bent wrong, missing bolts etc) Sh1t fit, due to bent flanges, bent tack welded bolts (more info below)
-How many miles since you replaced? about 250
-Have any codes returned? Yes, got a P2A03 due to exhaust leak
-Do you recommend, and any feedback? No I don't recommend, will be contacting Walker to see if I can get replacement cats and do this sh1tshow of a replacement all over again. Both cats had bent flanges on the front of the cat and the tack welded bolts seemed welded crooked so it didn't fit to the manifold flange at all. I grabbed a BFH and knocked out one of the bolts on each cat. Surpisingly they seemed to fit despite looking bent so I carried on. When I tried to connect to the b-pipe is where things when really wrong. They simply don't mate up correctly, as the nuts were tighting down the flanges never pulled together, instead I have a gap that is about the same width at the pipe gasket. I actually broke the factory weld on the B-pipe and had to reweld that, no pics because I suck at welding but belive I have that problem fixed. I've refitted the exhaust twice now trying to get a better fit. I completely disconnected the exhaust all the way back, including the hangers. I did notice that at some point while wheeling I snapped the metal that holds the muffler's front hanger point, not sure if that is contributing to my problem but pretty confident I just got crap cats. I have a bad exhaust leak on both sides.
 
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