I have a p0420 code have replaced both o2 sensors, mass airflow sensor, all 4 coils and plugs. Most were replaced before the code just in self preventative maintenance. 2010 Prius 179k miles. Car runs totally normal just throwing that code. I have attached the freeze frame. Is it the converter or is there anything I am missing?
Pretty much need to start looking for a new catalytic converter. The car is 13 years old and has the mileage to match. These things really only last 10 years or so.
In the Prius apparently this is turning out to be true in my Corolla 400,000 mi and still passes a sniff test The converter's not plugged doesn't smell like rotten eggs in the car is running great matter of fact same engine 2Z with none of the problems that the Prius which is regurgitating its own puke whilst running. Apparently the Corolla doesn't do this because if it's non- Atkinson cycle 2Z engine. And the Corolla can take an $89 welding converter being welded right in its pipeline and go right back to passing emissions and having a legal inspection sticker everywhere probably including California they make a welding converter that goes in that car that doesn't cost $1,500 It's only the Prius that gets the shaft apparently now I don't know there may be other models of car out there in the wild that have similar problems I only know the Toyotas and I am not in California.
replaced catalytic converter and still have the code, replaced o2 sensors. Can’t find any obvious exhaust leaks. Any other ideas? Lol
Okay I see this is in Knoxville Tennessee so what happened You bought an aftermarket converter a new Toyota converter a junkyard Toyota converter? To all.. I think in the Gen 3 or all of them the sensors have specific codes the '0420 is the catalyst is below threshold below the threshold of what? Some self flooding test at the car does every so often is discussed here. I guess so it's saying it can't run that test or something and it's failing the converter if it's a Toyota one and have a discussion with the Toyota rep at the dealer those personally I think this is a bunch of malarkey
