You can hack fix P0420 with oxygen sensor spacer; don't try anything else!

I know that the smog checks now just jack into the OBD port, but it would be interesting to see what the difference in numbers would be via a tailpipe type reading.
EDIT
. . . Not to be an illegality Nazi or anything like that, as I did my own license plate copy/mod, but you might want to add to your post that although unlikely, getting caught, could involve a good-sized fine.

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You did not state that you had to drill the small holes in the O2 as pictured.. None of the Prius O2 sensors have them holes…

 

Ok the oem sensor doesn’t have the 3 holes like yours? Also I can’t find that L adaptor…

 

My Amazon link would not post but search for
M18x1.5 Thread Adapter 41mm Brass Fitting Universal Connector Plug

I had to re-use one of the non foulers I previously had on mine because I could not get the adapter to tighten up in the cat correctly. I screwed one non fouler in to the cat, the adapter into that non fouler and then the sensor into the adapter. Been about 6K miles and so far so good.

 

Would this spacer work on a Gen2?

 

I have a stealth p0420 fix that can't be detected. Those antifoulers will fail a smog if the tech sees it. My fix works and it's undetectable. I will modify your O2 sensor or you can send yours in for modification. Check out my YT
If this isn't allowed please let me know. I'm just trying to save people from having to buy a way over priced new cat. Thanks

 

Sorry but what I meant is I can modify your downstream o2 or I can sell you a modified o2

 

That YT vid is worthless AI voice over stock imagery that provides zero details. What modifications are you making?

 

I got the right angle one but it puts the wire of the oxygen sensor right up near the exhaust pipe

 

I got about 14 of my friends to buy Priuses and one of them gave me his catalytic converter. I'm so glad that money indicated light is finally off

 

After the theft of two catalytic converters in less than a year span at two different places, I am done replacing it with OEM Cats. I installed supposedly EPA approved Cat from eBay, but the P0420 code never went away. I am in CA and smog is due soon. So I am planning to go through the O2 sensor spacer route. I am planning to buy this spacer to avoid drilling. Can anyone who has done this comment on if these specifications (46.5mm length) would work for Gen3.
1, Would I have enough space for the O2 sensor and cables. I would like to avoid L shaped ones that make them even more obvious at the smog check.
2, Also, this is just a spacer, does not have the mini catalyst as some others have. Do I need those or would just the spacer suffice for Gen 3 prius?
3, I have to DIY it as no one in CA would install these for me. Is it a straight screw in job? Any tips?

(Don't know how to upload an image, so attached as a file)

 

Wow it sounds like theft is a real problem where you are

 

Thank you. My smog check is due and I want to get it done in the next couple of weeks. Can you tell me the best way to go about getting ready for the smog test. After installing the spacers, do I clear the codes and wait to see what happens after I complete my drive cycle, or do I Iet the codes clear themselves after the drive cycle. When would I know if the spacer is working. If I clear the codes manually, how long does it take for the P0420 or P0139 codes to return? Ideally I would like to know as early as possible if the spacer is working and not wait for the drive cycle to complete, so I could try something else.
Also, what is the best way to tell that I completed my drive cycle and I am ready for Smog (assuming the codes don't come back).

 

I also have the dreaded p0420. My question about this solution is how will it affect the engine performance? The polution is not of a concern for me, but having a clogged cat is going to restrict exhaust flow. Which will force pressure back into the engine, no? In other words, bad mpg and potentially causing some components to fail from additional pressure build up.

I am wondering if cleaning the cat instead could be more of a permanent fix. Either by cutting it off and placing it in soap with water, or by spraying cleaning solutions (brake cleaner, etc.) through the O2 port with the engine running. I would avoid using anything that goes through the fuel. Yes they would work, but theyll also potentially damage your fuel pumps/line O rings, and in my case, it cleaned off and dug a hole in my headgasket and caused it to fail the same week i tried it.

Im happy i dont live in a state that forces a smog test nor vehicle inspections. Im more just annoyed of seeing the check engine light if im going to be honest. Im wondering if straight piping would give the prius better or worse fuel mileage.