P0420 Code

Bad news code came back this morning on the way to work so code was off for aboth 90 miles or so any ideas what to check now sould i go get the downstreen o2 sensor?

Thanks for the help

 

I forget, did you already have your cats replaced? If not it might be those.

 

Lol I'm no smell expert but I do know that a strong smell of sulfur is a good indication of the cats going out. Mine only smelled like that one or twice though under heavy throttle.

 

I don't even know what sulfur smells like

All i know is when my truck is on, I can "smell" a vehicle is on. None of my other 6 vehicles you can tell they are on by smell alone.

 

Yeah the 1st gens do have a more exhaust-like smell to them while running than later model Tacomas do, I think that's just because they're older vehicles with less emission controls on them than the newer trucks have. Sulfur smells like rotten eggs or a bad In-n-Out fart

 

Looks like the previos owner change the upstrein cat but the down one looks original . So those the 02 sensors

 

Your rear cat might be bad then. Usually when the first one goes bad, the 2nd one isn't far behind. That's why most shops will recommend replacing both even if just one has failed.

 

So u think in should change my 2nd cat ? Or 02 sensor fisrt .

Thanks for the replys eon

 

Why would you pressure wash your engine bay? That's pretty dumb/lazy.

 

The OP has been MIA since starting this thread but I totally agree....pressure washing the engine bay is asking for trouble. Forces water into places it shouldn't go. A light spray is all it needs, and I usually cover my fuse box, battery and alternator when I do.

I'd get a shop to confirm it's the cat before replacing it, that's just my best guess but it can be confirmed either by taking the cat off and looking through it (should be able to see light through the cat), or with emissions testing/diagnostic equipment. Aftermarket cats aren't terribly expensive but it would be good to verify before taking the plunge.

Otherwise, O2 sensors are less expensive so if you want to rule that out it may be better to start there.

 

Well after clearing code, exactly 317 miles till it came back again.

Now the question is, during the 317 miles, was there NO code, or was there a PENDING code?

As in, should I clear and attempt to smog it in January, and if it passes during the no code, get 2 more years out of it, or spend the $675 first for two new CATs?

 

I also heard (Google) the inlet side of the cat is supposed to be 100 degrees warmer than the outlet if cat is functionally properly. Check with IR detector.

 

What year is your truck? 99 and lower years are tested on older system which is BAR97 and 2 speed tested with tailpipe probe.you can have any 1 OBD monitor incomplete to pass.
2000 And up are tested on newer OIS without tailpipe. You can have 1 OBD monitor incomplete and only one allowed is Evap since hard to run on certain vehicles.
Even if code pending,as long as MIL not on and code set you should be good unless tech super anal and checks before hand.
I would clear light and drive and see if you can get monitors to set. If you can without light coming on then smog it. Just my :2cents:. Assuming you are in CA
I am a smog tech so I know the ins and outs

 

2001 2.7L
gimpomatic
4x2
210K miles

Yes car is in CA.

what does it mean "see if you can get monitors to set?"

What is your location?


I can find a smog guy that barely speaks english, that isn't a problem.


I can keep light off for about 350-500 miles on average.

 

I'm located in San Mateo area.
Monitors are basicly individual test pcm runs to check if systems have problems. If fails a test it with either set a pending code or hard code depending on problem.
My advice would be to get yourself a cheap code reader. When plugged in it will list all monitors for your vehicle.
If not ready (hasn't ran test yet) will say incomplete.
If complete will say complete.
On your year vehicle you have to have all monitors (tests) ran other than your evap monitor to pass OBD portion of smogs.
All makes/models are different as far as when tests will run cause all have to meet certain criteria. Toyota's are usually pretty easy to get them to run. Clear light first thing in morning without vehicle being on. Once cleared drive for like 5-8 miles staying under 55mph with gas tank 1/4-3/4. Once reached stay idled in gear for like 5 min and head back driving normal but let vehicle coast to almost a stop without applying brakes a couple times.
This cycle usually works pretty good other than german/euro cars
Let me know if this helps or have any more questions. If near San Mateo area I can scan it for you too.
Convertors as supposed to last life of vehicle if everything working properly.

OEM convertors for your truck will not be cheap.
$1500-200 If I remember correctly.

 

Yeah Toyota wanted almost $4k to do mine. I went with CARB approved Magnaflows for $675 installed.

OEM cats are far superior in quality to any aftermarket brand but they're stupid expensive. Even if aftermarkets only last me a couple years, I'd still rather pay $675 every couple of years than $4k at once at any given time.

 

On my 2003 Tacoma I’ve replaced both O2’s and cats cleaned Mafs. Got the P0420 code again. Saw I didn’t have the second o2 sensor all the way tighten. Tighten it cleared code now weighting to see if it comes back

 

It would cost me $116 in gas to come see you

If that means I can go 2 more years headache free, it’s worth it !!

I have the code reader
I use it with the torque app
I have to see how to get all monitors to run

I know how to use it to clear code

 

Update...

MY TRUCK PASSED SMOG! and I didn't have to bribe anybody!

The new cats paid off. The tech pointed out that the serial # on my TRD headers don't match the year of my truck and that he could technically fail me on that, but he didn't lol. Weird though.

Was worried about the 7th injector too since its not CARB certified but I guess he didn't notice it. I wrapped the braided steel fuel line in electrical tape so maybe that helped.

Anyway I'm pretty stoked . 2 more worry free years!

Reliable Smog in Duarte is a chill place with cool guys working there if you have to get smogged before the end of the year.

 

CONGRATS!!!!!

I am debating doing the 300 mile CEL clear and attempt to smog it. Or pay the $650 like you to do the CATS.