P0420 Code

Hey guys, I'm looking for some help here, I have this P0420 code in my Tacoma 2021 I got my catalytic stolen, and I got a replacement Converter; E.P.A. Compliant and add connected WALKER Oxygen sensor OEM Based, I have searched for leaks on my installation and P0420 shows up intermittently, sometimes it goes of and gets back randomly, any Idea any of you have had this code randomly like me?
what else do you recommend me to do before change catalytic again.

 

Bank 2 sensor 2. I had this code last month and O2 sensors and manifold/catalytic converter but i used OEM Toyota parts it wasn’t a cheap fix but so far so good. Did you put in new gaskets at the manifold and exhaust where it was taken apart?

 

Yes, I add the gaskets that came with the cat I installed, would you recommend to replace bank 2 sensor 2 sensor for a Denso one? or the whole cat for a OEM Toyota?

 

The po420 is almost a given with Toyota especially when going to aftermarket cats. To very generically explain the aftermarket cats dont have the capacity (minimal amount of metals) needed to meet demands. Oxygen saturation is sub o.e. and under certain conditions will fail programmed over stringent/unrealistic epa guidelines set.

Adding "o2 extenders" (soark plug anti foulers) will cure 99% of the time. Google is your friend

 

If you’re planning on keeping the truck for another 10+ years. I’d try to stay oem if possible. I would also be concerned about emissions based on where I live. If none of those things apply. Try the suggestion above. Id recommend some cat shields too. Sucks that people steal.

 

This is compounding the issue of less o2 saturation with the aftermaket cats. Less sensitivity not more as accomplished with extenders.. either that or spend $$$ on new oem cats.

 

And with extenders do you think emission checks will fail?
I understand that if I want everything as it was, I need to spend on Toyota OEM parts, but does the extenders help on that or just to remove the P0420 code?

Thanks for the guidance I really appreciate it!

 

Your right about staying oem if possible. Unfortunately in this case cost and over restrictive/unrealistic epa numbers are counter intuitive to the cause. Why buy an expensive oem cat at this point? Im no tree hugger but reality is extra wasted additional $, clean air and limited resourses are not needed.

 

+ 1 on O2 extenders. They’ve gotten me out of a jam a few times, however it might not pass a visual in one of the “commie” emission states.

 

Lets just say they are proven thru Ca. Bone headed bi annual test. Besides its proven effective, easy, and cheap and makes the system work as designed.

 

Edit: Freeze frame data on the DTC would help diagnose it. Most of the time a very small leak in that area will set a fuel system lean code, not a 0420……but it’s not impossible.

 

Thank you @1 Limited Toyota you helped me a lot I'll keep you guys posted when I install extenders, do you have any preferred brand or any one that you would recommend?

 

BTW were the cat(s) covereed by insurance (and they know it). They are obligated to pay for oem.
You now have reason to fight them for it.

 

As far as I know parts stores can't sell them. But they do sell spark plug anti foulers!
Amazon sells different types

 

@Rusty66 good advice I'll doble check I live in texas so previous inspections haven't been so rude.

 

I can't speak on if you should go to OEM CAT or O2 sensors but i can say that's what i did and installed them myself and so far ive not had a code or any more issues

 

My po420 was common after a pull up a Ca. Foothill grade. And then a relitively harder pull up on an in town hill. The (newish) aftermarket cats were depleted of enough o2 storage, set a code and of course put the car into open loop. This is not only causing extra inconvienance and expense but counter intuitive to the ridiculous epa set standards. Thats why I say the standards are over done/too demanding. The foulers "numb" the reading allowing compliance. Win/win.

 

Mine got to where it'd throw a 420/430 or both codes on long hills also, at the time the OEM cats were BO. The extenders worked as advertised. Mileage remains the same at 18~22 so I'm not too worried about it. Haven't seen a code since.

 

I diagnosed countless Ford P0420/P0430 codes by monitoring front and rear sensors. The front hego sensor should show the "up/down rich/lean" rapid switching pattern. The rear Cat Monitor sensor should have very little switching, mostly a straight line. The pcm counts and compares the front to back switch rates. (That is how Ford does it). I have given a simple explanation on a complicated matter. In Ford Mode 6 data I could actually see the counts from the sensors too.

 

Was insurance involved?