Catalytic Converter Replacement (P0420)

[fish0281]

So I've done everything but replace the cats on my '01 4Runner w/170k miles... the truck started getting lower than usual mileage (went from >300 miles per tank to <270) and shortly after, the P0420 code popped up. It has come and gone over the past few thousand miles and I've changed:

AF Sensor
O2 Sensor
Plug Wires
Cleaned TB
Cleaned MAF
Plug wires (plugs looked good)​

My CEL popped back on yesterday for a P0420. I think the only thing left to do is replace the cats I'm looking at Magnaflow cats (49505 and 49579); does anyone have experience with these cats? Any other cat-replacement advice would be much appreciated as well!:hello:

PS. I'm not interested in using an O2 simulator.

 

[fish0281]

Has anyone tried out Eastern Catalytic Converters (http://www.rockauto.com/catalog/moreinfo.php?pk=1317011)? They are much cheaper and they come with a 5-year/50k-mile warranty...

Also, according to the emissions tag, I have a 49-state system and not a CARB one... still has 2 cats, but not the tight controls required of California. SO, if my cat is running outside of the federal specs (i.e., 49-state), it could be in rough shape.

Anyone? Bueller? Anyone? Bueller?

 

[revenantdead]

what company made the 02 sensor you put in last time? that and how many miles are on that sensor?

 

[TheDurk]

Has anyone tried out Eastern Catalytic Converters (http://www.rockauto.com/catalog/moreinfo.php?pk=1317011)? They are much cheaper and they come with a 5-year/50k-mile warranty...

Also, according to the emissions tag, I have a 49-state system and not a CARB one... still has 2 cats, but not the tight controls required of California. SO, if my cat is running outside of the federal specs (i.e., 49-state), it could be in rough shape.

Anyone? Bueller? Anyone? Bueller?

If you have a 2001, there was no more Cali. /Fed. split and all trucks had the two-cat system. One set of specs for all states. CARB has tougher rules about the manner of testing and the approved replacement parts, but the specs are the same. Cali. specs were different only in '99 and '00. You have a 50-state Federal truck, not a 49-state. You may see parts that are not approved for sale in Cali. but it is because they have not passed CARB's own tests for replacements, and not because they don't work on the truck.

 

[fish0281]

Both the AF and O2 are Denso and brand new.

The tag inside my hood says EPA not California; doesn't the fed regulation say something like 75% while CARB says 95% HC/CO/NOX removal? I understand that all have 2 cats, but can you verify that there is no difference in the ECU (or its programming)? What would be the purpose of separate emmissions tags if there wasn't an actual difference in the Cali and non-Cali trucks?

I think I'm going to take off the front cat to see if I can get a visual on the catalyst bed to determine if it's heavily clogged and go from there. RockAuto is selling front and back cats (Eastern) for about $150 a piece, so that's not too bad if I replace it unnecessarily.

 

[TheDurk]

Both the AF and O2 are Denso and brand new.

The tag inside my hood says EPA not California; doesn't the fed regulation say something like 75% while CARB says 95% HC/CO/NOX removal? I understand that all have 2 cats, but can you verify that there is no difference in the ECU (or its programming)? What would be the purpose of separate emmissions tags if there wasn't an actual difference in the Cali and non-Cali trucks?

I think I'm going to take off the front cat to see if I can get a visual on the catalyst bed to determine if it's heavily clogged and go from there. RockAuto is selling front and back cats (Eastern) for about $150 a piece, so that's not too bad if I replace it unnecessarily.

I'm telling you there was no 'separate tag'in 2001. You are looking at the only one there was. There are no separate parts or builds in 2001. It's a 50-state build, end of story. The Cali. thing was over, as far as building the truck goes.

 

[fish0281]

So an '01 4Runner sold in California will have an emissions tag that says it abides by the EPA standards and not California standards?

To be honest, I don't really care. I just want to know if anyone has any first hand experience with an aftermarket cat on their 4Runners...

 

[TheDurk]

So an '01 4Runner sold in California will have an emissions tag that says it abides by the EPA standards and not California standards?

To be honest, I don't really care. I just want to know if anyone has any first hand experience with an aftermarket cat on their 4Runners...

I'm not 100% certain about the labels but I am certain about the trucks. So I'll let someone who has one answer the question about the label. But EPA standards and California standards were unified in 2001. I don't know why they would need different labels.

 

[fish0281]

So I have a family connection that can get me a pretty solid deal on exhaust work and I'm taking it in this weekend to have a master mechanic (specializes in Toyota) take a look at my rig. Most likely, they'll be putting in new cats for me, but they're also going to run a more thorough diagnosis on it just to make sure.

Does anyone have experience with Bosal converters?

 

[fish0281]

Is anyone familiar with an ECU flash as being part of a cat replacement?

The FSM doesn't really go into any detail in regards to converter replacement procedure, but I heard that the ecu would need to be flashed if new cats are installed... that was the first I had heard of such, but I have seen a couple TSB's about it for 4th gen 4Runners and some Corollas.

 

[GottaBeTRD]

sub'd
I'm interested in what you come up with here. My exhaust has a weird smell. Not the rotten egg smell but something else to where i assume I'm gonna need to replace it soon.

 

[spikeb122]

ever replace your cats? what'd you use, i'm looking at the eastern Cat's myself right now, and how'd you check them when you took them off?

 

[Nelsonmd]

First, if you have a question, just post in 1 thread, don't resurrect 3 old threads to ask your question 3 times.

Second, the eastern cat's are fine. multiple guys have gotten them, and they have lasted multiple years, in fact I don't think anyone has yet posted about one wearing out.

There isn't much of a check once you take them off. You can see if they have a broken comb or something like that, but other than that, not much more you can see once they are apart. If you ave a P0420 and you don't have a bad O2 sensor or exhaust leaks, then your cat's are probably bad.

You can try using one of those guaranteed to pass fuel additives to get you through inspection and just tolerate the CEL. Or you can put spacers on your O2 sensor like someone else mentioned to take the sensor out of the exhaust stream, but technically that is illegal, and if your state does actual inspections like Cali does, they might catch you.

 

[Robb235]

I got 99 problems but a P0420 ain't one!

Here, give this a shot:
http://www.toyota-4runner.org/3rd-gen-t4rs/175242-how-make-your-own-rear-o2-simulator-$5.html