So I just threw a p0420 on my 2004 bone stock 2.4 single cab tacoma. It has 183k miles. Apperantly this can be several issues from what I have read on the forum and first thing tomorrow I plan to
1 check for exhaust leaks
2 clean MAF
3 test both O2 sensors

and if none of those seems to be the culprit I am planning on replacing the cat converter because after 183k it probably needs to be done anyways. My question is this - I have heard that you have to get OEM from toyota or else you will keep throwing the p0420 code is this true? Has anyone gotten a magnaflow or catco cat converter or any other brand for that matter and not thrown the p0420 code after? From the dealer I have read is over $1000
thanks
Ryan

 

for OP....mine is making a vibrating noise at certain rmp...so annoying, and sounds like crap

 

I have never heard that you have to go OEM.
I've read mixed reviews about magnaflow and I think you have to get it welded in.

I just got this one in the mail and it seems great quality...
http://www.converterwarehouse.com/ca...oductID=151273

 

I have been looking it up online today for awhile and have read several sources say that a non OEM will only last a year or so then will need to be replaced again. Also I have seen many of the threads on this issue (p0420) go on and on for ever with the owner replacing every single part possible and still getting the code. I am thinking about just getting one of these:
http://www.urdusa.com/product_info.p..._id=1260518914
looks like a fix all only if your engine eventually throws a real code you will not know about it

 

There is a reason why you have to go OEM on the cat but there is a way around it. In 2001 Toyota made all their cars 50 states legal so they have to conform to the peoples republic of Kaliforina CARB standards.

What this means is that normally the ECU would flag the 420 code if when the cat converter got below some where around 75% efficiency.

Well with the CARB standards it will flag a 420 code when the converter is some where around 95% efficiency.

This is where the problem with aftermarket cats come in. Just about all non-OEM aftermarket cats are designed to meet federal emissions and not CARB compliant. Because of this they are around 90% efficient at best when brand new causes the ECU to throw a code. The OEM cats are in the high 90% on efficiency.

You didn't say where ya live so I will assume its not in The Peoples republic of Kalifornia.

The easiest way to solve this problem is just get a aftermarket high flow cat and buy a "sensor simulator" from TRD products. What the simulator does it modify the signal from the O2 sensor to make the ECU think the cat is work at 100% effiency all the time thu no 420 code.

This is the route I took with my 4runner when I couldn't get ride of the 420 code.

On a side note isn't it ironic that the code for bad emission 420 is the same as the code for national pot head day LOL.

FOG

 

Yes, thanks for the info. This is the route I am thinking about taking. How long can I expect an aftermarket cat to last before I need to replace it since I will never get a 420 code again telling me its bad? 100,000 miles? also, do I need to replace the o2 sensors also or can I just leave them in there with the new simulator?

And by the way I live in Arizona and in a county that requires no emissions so Im free to cut off my exhaust with a hacksaw if I want.

 

Also, the truck has been sitting for around 6 months and I left just enough gas in it to get it to the gas station. So when I started it back up and got it to the gas station to fill it with new gas (91 octane) and a bottle of lucas cleaner then drove for about 30 minutes and that is when the code came on not sure if maybe this has something to do with it? I did reset the code and it came on about an hour of driving later but I'm sure there is still a tiny bit of old gas in there still. I may wait it out for awhile a reset the code after I fill up once more with new gas.

 

Actually no you can't cut off your exhaust. As I said earlier there are two types of emissions standards CARB and Federal which governs all states EXCEPT The peoples republic of Kalifornia.

So your vehicle was built with FEDERAL emissions standards which your not allowed to tamper with or disable. However putting a normal cat on a CARB vehicle will make it FEDERAL emissions compliant.

And yes a normal aftermarket cat will get you 100K miles. The 02 sensor should be fine and the sensor simulator should solve all your problems.


FOG

 

I have the exact same code. Had it for a while now. I just keep a code reader in the car and clear it when it comes up.

I suppose one day I'll have to get the simulator, but I just don't want to spend $120 to not fix a problem.

 

Except that you have to break the FEDERAL law to do that. FEDERAL law prohibits turning a KALIFORNIA emissions vehicle into a FEDERAL one. Cars must be maintained as they were built as far as emissions go. (Not that I care.)

 

You will still see all codes except P0420.

 

It doesn't matter what state you're in, federal emissions standards say that you must use a direct OEM replacement part if you need a new catalytic converter and that you may not tamper with emissions control devices. Many areas just don't require inspections and/or emissions testing to help enforce these laws.

-Dan

 

This sounds like a problem easily solved by an O2 simulator so....x2 on that

 

I would run the O2 simulator and aftermarket cats.

This is how i see it--Do what you can but dont buy into everything or the monopoly.....

 

U want ironic ?

my rear O2 blew the 420 code on April 20th.

 

Yeah, but did it inhale?

 

That depends on what your definition of "did" is...

 

Hey guys, my girlfriend has the same problem with hers. She's got a 99 4runner and I've been looking a lot around this and other forums. Basically what I've concluded is that Catco works well with the 4runners and I don't believe I'll have a CEL light issue after I install them.

I do know OEM would be better, and don't have the Cali issue to worry about. Just wanted a general consensus as to others with experience of aftermarket cats.

 

I had the code 420

2000 3.4 125,000 miles i replaced the whole exhaust system with Walker exhaust and 2 new denso sensors .

Not sure of the mileage but it has been about 9 months.

The code cleared itself and has not come back.

 

hmmm.