Here are the specifics:
2000 4Runner 2WD
v-6 SR5 104000 miles
East coast vehicle

I got pep boys to read the OBDII which gave 0420 code, then cleared the message. Running smooth.
I have been reading a bunch of messages online. I looked underneath to see what I have there.
I dont think this was a California vehicle but who knows really? I expected to see the muffler and an obvious catalytic converter "A", but then I saw this other thing "B". What is "B"? Also. what are the best steps to take now? Should I replace 02 sensors before anything else?
Should I replace the cat anyhow? If so, what cat can I use? I attached the cat photo so you can see what sort it is.
I'd like to do this myself if possible. If I can avoid an expensive shop repair, it would be good. Business has been pretty bad lately so the timing of this really is poor.
Thanks in advance!
D

 

I took a look online - the fix is costly (both the O2 sensors and the cat). I would disconnect the battery to clear the code and see how long it takes for the code to be thrown again. Some times codes will throw, they're cleared, and they don't come back again, or it takes a long time for them to return. It would be a good indication of how bad the O2 sensors or the cat are.

 

Looks like a Cali. to me. Lots of Cali.'s were sold in the East, including my '99 (NJ). As suggested, clear it, and see what happens. When I first got my P0420, it would take a few months to return. I kept clearing it (I have a scanner) and eventually it would return within a tank of gas. My front A/F had been done 15K before, so I replaced the rear O2 and the P0420 never returned. You can get one--make sure you get a Denso--for a good price on Amazon and do it yourself. You may need new stainless nuts from the dealer as they tend to rust out. You can get someone with a good live scanner to tell you if it is the sensor or the cat, but the cost difference is so large that doing just the rear sensor makes sense unless you are certain it is not old (70k+).

 

You have a Cali model with two cats. I just had both cats replaced because I've had a 0420 code for 2 years. I also replaced both the A/F and 02 sensors.

Try replacing your sensors and see if that works. You could also just keep turning off the CEL but don't be surprised if keeps coming back more often each time.

Erich

 

URD sells a rear o2 simulator. It will make the code go away, but the problem will still be there.

 

So you have a cali model with a code. it is either the O2 sensors or the cats. Each cost quite a bit of money. Like I was saying, the frequency of occurrence is an important factor. Give it a go and report back. It won't cost anything.

 

I had the same code I needed a Muffler also so I ended up replacing the whole exhaust system from the crossover pipe back.

I used all Walker exhaust parts then I replaced both the sensors with Denso ones from URD put it all on and the code cleared itself and has not come back in over a year.

Yes I was also surprised by my East Coast Truck having the California emission package.

I know alot of these trucks on the east coast have this package perhaps the Naviguesser of the boat gets lost easy and one port looks just like another after a while.

 

how many miles do you have in it?

if its over 100k, its most likely the O2 sensor.

Did you notice a drop in your miles per tank of gas?

usually, the front one goes first, followed by the speed sensor.

Go oem with these things if you replace them.
you might want to start looking underneath to see if you'll need 2 new nuts.

 

I'd venture a guess that this emissions issue is going to become a common occurrence for most 1999 Cali 4Runner owners, just like the "strawberry milk shake".

It will be interesting to see which fix is the best in the long run:
1. New Cats
2. URD Simulator
3. Driving around with a CEL all the time.

Erich

 

All 2001 and 2002's plus 2000 Cali's have the same setup. The '99's are at least a year older, but the cats should have a few more years in them as long as they do not suffer physical damage and the engine is kept running in good tune and trim. Regular maintenance, including MAF and TB cleaning, plugs and wires, changing O2 sensors and fast response to MIL's is key to protecting those valuable cats.

 

yeah, I wasn't sure what other years had the same exhaust. What is the normal expected life for these cats?

Erich

 

 

Durk, I'm a newb w/these acronyms. Could you please explain what you mean with: MAF, a TB, and MIL? Thanks.

 

MAF = Mass Air Flow Sensor - It is a sensor in the intake tube between the filter and throttle body that measures the amount of air entering the engine.

TB = Throttle Body - Controls the amount of air entering the engine.

MIL = Malfunction Indicator Light - More commonly referred to as CEL or Check Engine Light

 

Thanks, now I know more of what everyone is talking about!
Last month, while on a trip to Colorado, I had an overheating issue andended up having a dealer in Colorado Springs change out my Rad, therm., hoses, cap, etc. While there, the mechanic checked other things on my vehicle as I have had the VSC CEL on for over 18 months. I was told that the Cat Converters had "effieciency failure", and I would most likely need new ones in the very near future. Vehicle runs great, and drove over Mts., Kansas prairie, etc. putting over 2500 more mileage on the Runner before getting home to Florida. Everything still sounds & runs great. The CEL had stayed off for a few weeks after the dealer mechanic reset it. It's on again now. Nothing was said of my O2 Sensors. How will I know when those CATs should be replaced? Does it hurt the truck to drive around all the time w/the CEL on?

 

2000 4Runner/East Coast/Cali Emissions:
Just got this 4Runner last month. Surprised (as most here) to see the Cali setup. This thing had the code (I assume) so long that the previous owner burnt out the CEL. I changed the bulb, cleared the code, and it came back w/in 50 miles! Got URD's rear 02 simulator on the way. Getting 19 mpg so I'm really not too worried about performance (CC set to 68mph on highway). I'll return with results. I need to thank all you people here for the great info!

Sorry meant for title to be "Same 420 Code"

 

Yeah, I have it too. It's not a big deal if it isn't keeping you from getting inspected. The rear O2 doesn't affect the performance of the vehicle at all, it just throws codes, so no need to worry about it. Your vehicle doesn't NEED new cats, it's just that gov regulation may require you to get new cats. Take that for what it's worth, to me it's not worth much, so I am not changing my cats.

 

Today, I called the dealership back in Colorado Springs that did all the Rad work, etc. for me, and gave me the news about my CATS. I spoke to my service guy, and got a few particulars on my problem. My mechanic there had actually put the CATS through some tests, and mine would only achieve a temp. of 1250 F, whereas optimum normal operating range is between 1500 F and 1700 F. This inefficiency will affect the engine's performance, which I experienced on some steeper grades in the mountains. Service guy told me I could drive it like this for awhile, but to start saving my money as this problem will definitely have to be dealt with in the not-so-distant future.

Also, the O2 sensors were both checked and were not a problem, but Service Guy recommended changing them out w/the CATS if it's been over 100,000 mi...which it has.

My BIG question now revolves around the best but least expensive route to fix the CATS. Do I have to go OEM, or are the aftermarket CATS suitable? If so, which ones are best? Are "used" OEM CATS even an option I should consider? I don't live in California and have no smog test to pass, but would like to keep my Runner in good performance condition. Any & all replies are welcome...especially from you mechanic dudes out there in Yota Land.

 

LOL! Me neither...well not yet anyway.

 

Update:
Installed the URD rear O2 sim. Cleared 420 code.
200 miles later no CEL and so I brought it in and got new MA inspection sticker.
New sticker Pass- "Catalyst Monitor-Ready- No OBD Codes
I hope this helps folks save time and headaches!