Toyota PO420

[Nelsonmd]

Holy cow guys... Give it some effort!

This is discussed to death in the documentation and tutorial thread. It's stickied, it's not that hard to find

Master Directory of Informational Threads --- A MUST READ For New Members
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3rd Gen FAQ, Tutorials, & Documentation Reference v2
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Denso o2 Sensor

If this is your first time hearing of/seeing the master thread/tutorials and documentation thread, then stop posting anything, go find them, read through them, and remember to always check there first before posting questions. 90% of your questions will be answered there and in a clearer, more complete way than if you just post the billionth new thread about ridiculously common issues.

Sorry if that comes across as curt or insulting, I don't intend it that way. I just really want you to go to the place where literally ALL the answers to your questions are clearly stated with pretty pictures and detailed explanations. We all like pretty pictures.

Also, download the FSM. It has diagnostics and explanations for every code. If you read that, you will find that P0420 can be caused by an exhaust leak or by a bad O2 sensor as well as by a bad CAT. Both are much cheaper to fix than replacing the CAT (and much easier!). But if you do have to replace the CAT, again, the tutorial and documentation thread comes to your rescue, there is a detailed walk-through for how to do that.

And if you searched for CAT replacement, you'd probably find that there are aftermarket CAT's available for about $300 total (for both CAT's) that bolt right up and take care of your code. I'll let you find the brands in those threads. It's pretty easy to search for (literally the first 3 hits I got had that information in them clearly stated...)

 

[sugjavier]

I kept getting this PO420 a year ago, all I did was replace the o2 sensor and I never got it again after the install to this present day. Depending on your year/model, you might need another kind of Denso o2 sensor but this one did the job for me.

 

[beer-toe]

[MENTION=56021]Nelsonmd[/MENTION] I appreciate that you went out of your way to help. I do use the search and now how stuff works. But what makes it hard is that people do create a million threads so instead of reading through one I have to read through a bunch to pick and pull what I need. At least I am searching for old threads to ask a question instead of creating a new one.... But I did come across this as awesome tool to use since I couldn't navigate directly on denso website
Oxygen / AFR Sensors - Underdog Racing Development

And if that fails I will look into it further but hopefully not.. Thanks for the help guys it makes things a lot easier searching and getting feedback from people who have dealt with this before...

Stay bless

 

[Nelsonmd]

Yeah, I do appreciate that you didn't start a new thread, but in this case, your O2 sensor question is very clearly answered in the stickies, and your CAT question was quite literally answered on the first page of the first 3 results when I searched for "cat replacement". If you had to go through even just 1 page of search results to find your answer, I'd give you a break, but it was in the first 3 results... plus if I direct you there rather than give you the answer, then anyone who finds this thread later on will know where to go for the answer.

The tutorial and reference thread is a little buried since it got buried in the master thread sticky; I wish the admins would pull it out and just move it to the very top of the stickies, but seriously, look through it and see what's in there. It really does have some of the best and most complete answers to so many common questions like the ones you're asking. And a couple of those links like the buyers guide have such a good and complete explanation of the basics, I hate seeing the hard work of the guys that wrote those threads not being used and people just posting new threads, or resurrecting a useless one. Using the reference threads also prevents you from getting bad or inaccurate advice.

And again, I don't mean any of this personally or insultingly. Spend some time here and you will feel the same way. It will get harder and harder to find the good information that you have found by searching here extensively, and you will come to really appreciate the investment guys have put into the reference threads that provide the good answers. You should see my 4runner bookmark folder, I just had to start bookmarking every good thread I found because I knew it would be difficult to find them again...

 

[baja1]

interesting about going through puddles! everytime I rumble down a rough desert road I generate a PO420 code, put on the scanner,clear it and am good to go till the next bumpy road!
and what, no 420 jokes!:naughty:

 

[jeremyc74]

interesting about going through puddles! everytime I rumble down a rough desert road I generate a PO420 code, put on the scanner,clear it and am good to go till the next bumpy road!
and what, no 420 jokes!:naughty:

Your O2 sensor is on its way out. Ever see a light bulb that goes out, and you can tap it and get it to come back on? Similar failure in the O2.

 

[beer-toe]

[MENTION=56021]Nelsonmd[/MENTION] I had no idea those stickies existed. I must say I'm new to t4r but not to Offroad forums. I know how a lot of it works. I don't take comments or peoples help as being a dick. So don't think I'm trying to defend myself, but thanks for sharing it will def. Help me.

And I think you had me mixed with someone else posting about the cat, all I wanted to know is if I had the right part number. I know searching denso website you can look up your vehicle. But I'm assuming since mine is so old nothing came up as a result hence why I asked here....:banana:

 

[beer-toe]

But let's,continue with awesomeness that t4r has to offer

:tea:arty:

 

[TheDurk]

[MENTION=56021]Nelsonmd[/MENTION] I had no idea those stickies existed. I must say I'm new to t4r but not to Offroad forums. I know how a lot of it works. I don't take comments or peoples help as being a dick. So don't think I'm trying to defend myself, but thanks for sharing it will def. Help me.

And I think you had me mixed with someone else posting about the cat, all I wanted to know is if I had the right part number. I know searching denso website you can look up your vehicle. But I'm assuming since mine is so old nothing came up as a result hence why I asked here....:banana:

They completely screwed up the Denso web-site. It used to be the goto source, and provides lots of good info only available there, like wire length and detail pics of the plugs. I recommended it for years, but now it's FUBARED as far as finding part numbers for applications. So it's back to URD.

Matt-- [MENTION=56021]Nelsonmd[/MENTION] may have jumped on the wrong guy this time, I'm afraid. It's Denso's fault. But the post was valid in general and is good info to the next noob looking at this old thread.

 

[jeremyc74]

They completely screwed up the Denso web-site. It used to be the goto source, and provides lots of good info only available there, like wire length and detail pics of the plugs. I recommended it for years, but now it's FUBARED as far as finding part numbers for applications. So it's back to URD.

Matt-- [MENTION=56021]Nelsonmd[/MENTION] may have jumped on the wrong guy this time, I'm afraid. It's Denso's fault. But the post was valid in general and is good info to the next noob looking at this old thread.

Rock Auto is a decent way to cross reference the part numbers too, even if you're not planning on buying from them. Unlike a lot of sites they give you the MFG part numbers, and with the Denso stuff even the OEM parts they replace.

 

[ajonesnv]

Common the problem is super clear and simple....your Runner just wants to smoke a joint.

 

[Nelsonmd]

You're right, I missed on the cat thing, that was the OP, but the O2 sensor information was there as well. I stand by my urging you to look in the stickies.

Sorry for the misdirected comments, my bad.

But still check out the stickies...