aquasport17

I've read countless threads here on this code and havent found one of them that resolves the code. There are too many people with the code for there not to be a resolution. Lots of "did you try" .... but no final resolution.

Has anyone had the code, and fixed it by replacing a cat or sensor, etc? Specifically I have a CA emmissions truck.

Jeff

My814x4

Replace the cat it is bad. There is a O2 sensor in the frt of the cat and one behind it that lays there looking at what is coming through the cat if the cat is doing its job then it does nothing but if the rear O2 sensor starts to see the same as the front O2 sensor the cat is not working and then sets a 420 code.

aquasport17

was afraid of that. toyota part probly 800 bucks right? There is also TWO converters on my truck - any guess which it would be? The code is for bank 1 but I don't know what sensor that is.

Elton

you try cleaning the maf sensor ?

mastacox

I'd check junkyards first, just in case. But, with how cats are selling right now, there probably won't be any lying around...

heddleston

I had to replace my Cat's but the 4runner was under 80K so it was free. I have the CA emissions dual Cat too. I have also replaced my A/F sensor (engine side of the Cat's). The computer gave me a different code for that and it was easy to diagnose and correct. The A/F sensor lasted longer than the cats.

Here in VA they can test the Cat by hooking the exhaust to a machine, I am sure you have that out there too.

My Cat did have a Land Cruiser sticker on it when it returned fixed. I wonder in they share the same dual cat system?

Good luck, I got the P420 three times, I would reset the computer and in a month the code would come back. It has not happened since the replacement.

Jonathan

MTL_4runner

Ok a few things here. First, the P0420 code can be caused by a couple of reasons (bad front O2, bad rear O2, exhaust leak before the converter or even the converters themselves going bad). The reason why the vast majority of the trucks that get this code never resolve it is usually because the final step to fixing the problem is the actual replacement of the catalytic converters and it is a HUGE expense.

To compound that, unless you can get lucky and find yourself somone with a parts vehicle to get one from, most junkyards are prohibited by law from selling used catalytic converters (they are only allowed to recover the precious metals as scrap, but that's all). Therefore that leaves the only real option; buying a new one from the dealer (and that pricetag doesn't include any KY, but it ought to!!!). There are a few places to get OEM toyota stuff at a good price (Toyota of Dallas - Phil and Northridge Toyota - Evan, both can get you a much better price that you can get locally so check with them). If you're lucky, the converters may actually still be under emissions warranty so check with the dealer before you go through the expense of replacing them yourself.

Finally, there is a way around it, but if you live in a state like Cali or anywhere else that does thorough emissions inspections and testing, getting caught with a device that can be a serious fine so I really don't recommend it (although it would be a heck of alot cheaper than a new converter).

aquasport17

Thanks guys. Yeah I cleaned the MAFS. Do you think I will need both cats, just the front, just the back?

MTL_4runner

Sent you a PM.

Usually you need to replace both, but maybe Jonathan can elaborate on what the dealer replaced on his truck.

heddleston

It is one piece. I think I remember reading discussion on this forum about replacing the 2 with one but I don't know if anyone actually did it. From what I read it would be a challenge not to just replace the whole thing.

As previously stated there is a way to trick the computer but the cat is federally regulated and my understanding is that it's a federal offence if you are caught. Not to mention that these parts are there to help keep our air clean.

How many miles are on your 4runner?

mt_goat

I was throwing a P0420 every other day. I "fixed" it with a URD O2 simulator, and haven't thrown a code since (for off-road use only of course)

BTW if you decide to replace the cats, I have a set of front and rear 2001 5VZ Taco cats with only 27,000 miles on them that for the right amount of bribing I'd consider letting go of.

MTL_4runner

It has been done a few times (replacing the 2 with a single converter) and every time I've heard of someone going that route it has failed. Unfortunately only the 96-00 non cali emissions trucks can get away with the single converter replacement (they only had 1 converter to start with anyway). I've never heard of anyone welding in two aftermarket converters inline though so you could trail blaze there a bit if you felt like it. I believe Heddleston's right, it is a single piece (ie you can't just replace the front or rear cat), but don't quote me on that. Call the dealer and check.

I don't suggest overriding the rear O2 sensor as was suggested above, but to each his/her own.

aquasport17

Will the TACO setup bolt on to my truck? I have CA emmissions

mt_goat

I don't know. They are from this 2001 ext-cab 4x4 which was originally purchased in West Virginia:
http://rides.webshots.com/album/383446112ZpbXpN

mt_goat

Here's the rear cat:


I'll look for a pic of the front cat.

Here's one of the front cat upper bolt flange:

mt_goat

Yeah I'm running with one Carsound cat after my swap and the 2001 ECU was very upset with me. But since I tricked her with the sim she doesn't even know I'm cheating on her.

Is that in general or because he's in Ca.? I know somehow TRDOLMAN got away with removing both his cats in Ca.

MTL_4runner

I forget what Dave ended up doing, maybe Mark (midiwall) will chime in on that. I never suggest bypassing the cats not only because it's illegal, but it's also bad for the environment. The guys running superchargers often have a tougher time because when you play with the fuel maps to get more power, you often are running fairly rich on a regular basis (which can kill the converters alot faster than a N/A motor).....that's why Gadget finally came up with that work around because almost everyone 2001+ was running around with a constant P0420 code.

The O2 sensor signal conditioner will definately rid you of the code too.

aquasport17

Will it bolt right up to my 00 ? What do you want for it?

mt_goat

See posts #14 and #15. Does your 00 have the newer style exhaust manifolds? They started using them in 01 on the Taco, but I don't know about the 4runners. They look like the ones on this engine:



I'd want quite a bit for them because there is some talk here of starting emission testing in a few years and they may come in handy if that happens. Plus the last cat I took to the recycle place fetched $140 cash just for one old 93 cat. But I'll consider offers.

aquasport17

Well lets start with - will it work. Looks pretty similar ....Here are some shots of what I have ....

Passenger side shots ... (no comments, I live near the salt water and I am on the beach every weekend - I don't wanna hear it)