P0420 please help :(

That's a really odd issue. You can give one of these a try: Paladin Straight O2 Oxygen Sensor Extension Spacer CEL Fix 55mm - M18 x 1.5 | eBay

Note: This works for me but my driving felt exactly the same before and after.. so do not know if it's something else causing that issue.

 

What code reader did you use?

Your car is 12yrs old and probably has A LOT of miles.

CAT is probably dead/dying due to years of oil consumption. The Gen2s are known to burn oil. Excessive oil consumption will lead to an early CAT death. Do you know how much oil the car consumes between oil changes? If the car is burning a lot of oil, this will kill the replacement CAT quickly; essentially you will need to resolve the oil consumption.

All those additives are a gimmick and just enrich the manufacture's of the snake oil.

STOP wasting your money on gimmicks. The ECU will detect something is amiss and will throw a code some time later.

You live in SF. Take your car to Luscious (SF) or Art's Automotive (Berkeley) for a proper assessment and repair options.

CARB Cats are expensive b/c the manufactures have to certify that the replacement converter is as efficient as the OEM, and they must also provide a longer warranty. This longer warranty is the reason CARB Cats are expensive.

Some people just do a bolt-on/weld-on Cat. Don't be surprised if the cat does not last long. I remember one person went this route, and the Cat only lasted a year.

 

Those readers don't always see the Toyota/hybrid specific codes but only generic OBD codes common to all cars (like the p0420). If you're still on the original HV battery, the lack of power and additional warning lights/codes could be caused by it.

 

Yeah find out if it's a genuine Toyota battery or an aftermarket unit. Lots of issues with those rebuilt packs. Anyway, get the codes read with a good reader. Those companies mentioned have very good reps.

 

That’s very bad. Why would they check how much oil is in the engine before changing it? So your engine could be using a lots of oil and get damaged and you won’t even know about it. It’s owners responsibility to check the oil level. Owner’s manual will tell you that and how to check it. Why do so many people just fail to check it?

Any place is able to fit Toyota OEM catalytic converter as Toyota does sell it as a part.

 

WHAT ??
You do know that you can check the oil yourself.....right ?
And you really SHOULD do that at least a couple of times between changes.

 

The rear O2 sensor could be off or it could be the cat. I had a new dual cat assembly sent to a friend out of state than shipped to me.

Posted via the PriusChat mobile app.

 

also if youre under 150k miles the dealer will change them under warranty! 15 years/150k.

 

Welcome to PriusChat!!

How many miles on this vehicle?

If you don't know much about the vehicles history (service, repair, owners, etc), you can look some of that up by registering the VIN at : Toyota Owners Official Web Site

And the link for owner related manuals : Toyota Online Owners Manuals and Warranty

It sounds like you may need access to a better code reader, as you may not be reading all of them.

Were there any other codes read?

Are you clearing the code(s) after each reading?

On a side note, if the 'oil can' warning light hasn't been seen on the dash you could be ok (except for the previous owner). Either way it might be time to start checking the oil between changes. How often do you have the oil checked/changed, and what type of oil is used? (oil with a lower 'SAPS' can potentially extend the life of a cat)

Yes, the OEM cat is the only legal option in CA (or NY) that I know of. You might be able to get away with finding and installing a used cat. I saw one for sale locally online, but it could just be a clogged up hand me down headache. You could travel and buy/install a used one from out of state, and I bet there are shops in Reno/Draino doing such business.

The last time I went for a smog/emissions test the tech looked under the car for the cat (using a telescoping mirror), I asked him if he had ever seen an aftermarket cat on a Prius before and he said no. I then asked if aftermarket C.A.R.B. cats were available for the prius as the OEM costs so much and he said yes, then I corrected him

If needed, I am local and have a mini-vci cable you can borrow for code reading.

Some reading material that you might find of interest :

Catalytic Converter Clogged - Glazed Over | PriusChat

2006 Prius 140k miles: Rebuilt battery replaced 4 times in 1 year - decision to keep or trade? | PriusChat

Oh, and how many miles again?

 

Dang just 5k over the legal warranty limit. But it seems you've taken care of the issue, so congrats irregardless

 

How did the old cat look down the pipe? Hopefully code doesn't come back.

Posted via the PriusChat mobile app.

 

There are some good local shops around the bay area .

You can try Arts Automotive in Berkeley or Luscious Garage in SF. They are hybrid shops.

Do you have a code reader and is it still the cat code that is being displayed?

Good luck and keep us posted .

 

10years/150K miles.

OP is over by 2years (2018-2006) and 5K miles (155k - 150K). Out of warranty by both measures. OP could have tried for Goodwill Assistance. But unlikely since has not been patronizing anToyota dealer for paid service.