Help taking off po420 code

I’m having a problem with my 2011 Tacoma it starts to stutter between 30 to 45 mph, I’ve changed the spark plugs hallowed out the cats on both sides; installed new o2 sensors still the code po420 comes out any suggestions that might help out.

 

Well since you have ruined the Catalytic Converters it is no wonder...

This is what the manual says are trouble areas for that code:

•Gas leakage from exhaust system
•A/F sensor (bank 1 sensor 1)
•HO2 sensor (bank 1 sensor 2)
•Exhaust manifold (TWC)

Oxygen Storage Capacity (OSC) of Three-Way Catalytic Converter (TWC) Less than 0.04 g

 

I had this code. It turned out to be a gasket connecting the rear cat to the Y pipe.

However, since you've gutted the cats, I think you're always going to have a code of some sorts.

Good luck

 

Going with the hollowed cats as the culprit. Make sure the new O2 sensors you replaced are Denso and not Bosch.

 

https://www.youtube.com/watch?v=krD4hdGvGHM

 

Did you hallow out the manifold cats or the down stream cats. or all 4. Because it will send codes anything upstream of the O2's

 

About 2 days early for friday there chief

p0420 is catalytic converter efficiency below threshold, and if you're cats are hollowed out, they're about as inefficient as they can get

 

the catalytic were already going bad took to the shop they wanted 2500 to change both sides

 

The pcm needs functioning cats to be happy. You can either live with the CEL or put some cats in it

 

All four I had to replace them just didn’t wanna pay 2500 so I just hallowed them out

 

Then you're going to have to live with the cel if you you don't want to fix it right.

 

As long as it still runs well just use this custom mod that the dealership used on my truck... Electrical tape is cheap.

 

gonna try it

 

I was joking, but if the CEL bothers you that much it's your truck

 

Since your cats are toast, if you want to get rid of the CEL, you're going to need to move your o2 sensors further away from the exhaust stream. You can use 2 spark plug foulers, and drill on out for the o2 and the other is attached to lengthen. OR you can buy them pre made. Something similar to this:
https://www.amazon.com/Oxygen-Fitti...cer&qid=1616600387&sprefix=o2+,aps,167&sr=8-3
Yes the light will go away if it is indeed your cats that are the cause, you will pass emissions, you may not pass a vehicle inspection if they check for that type of thing in your state though.
This will fix your issue. It's a pretty common thing for people to do.

 

Does you state do emissions testing? Or plug into the OBD port for error codes?

If either you may be

 

For documentation purposes, I had the P0420 code and intermittently P0430. Two shops said the catalytic converters are bad and to just replace them. This seemed pretty unlikely for a truck with 170k and never had any fueling or engine issues which destroys cats.

When I hooked up the scanner and checked the inlet and exit temperatures (pre-cat and post-cat) they were basically identical. This would have been a clue if one was bad.

I decided to start with the simple and replace the gasket at the base of the cats. Upon taking mine out they were quite crusty and falling apart. Which was a good sign of leakage.

5k miles later and no check engine light.