P0420 Catalyst System Bellow Threshold Bank 1?

A minor update. My oil was low when I checked the dipstick a little while back, likely at least two weeks back although maybe even three weeks. I did not check afterwards but likely added about two quarts. Likely driven anywhere between 700 and 1050 miles between then and now. Checked it just now and the oil level is still pretty high so I don't think the engine is burning excess oil.

Have not interrogated the computer yet. Have so many things on my plate that I often lose track of things.

 

Some minor updates and questions. I have a new catalytic converter I got from Rock Auto. Figured more trustworthy than eBay and decided to order it before tariffs make prices go insane.

I do know of an old man who used to work on exhaust systems. He was cheap but did a good job. He is a short "Prius" distance from home even though I moved. Figure check if his shop is still where it was. If I can get him to weld it, should I?

Also, if I remove it myself, I know someone who welds. In such a case, would I be better off getting it welded by him or better off clamping it? Concerned that if the fitting is not perfect and welded, might not fit?

Also, if I end up doing it myself, I have a grinder. Would that work for cutting the pipe or would I be better off getting a reciprocating saw as is used in this video at the 7:00 mark?

Also, I want to clean the intake system a bit. I was thinking about spraying to down at least real well with throttle body cleaner. I have removed throttle bodies in other cars to clean them but would prefer to wait on that. There is a video where the person did not want to push on the throttle body to get the underside. Is that an actual concern?

 

Update: I ended up going to a shop to get the catalytic converter replaced. Ed's Muffler Shop if interested.
It is the older person I mentioned last post and has been around for I think decades.
Charged me $100, so not bad.

 

I don't know but will post an update in a little bit (few days to a few weeks.)

At the shop, Ed's Muffler shops in Chesapeake VA, Ed did say that the O2 sensor in the cat looks good. he said that usually bad ones look black and/or scorched . Doesn't sound like he works on hybrids often but has DECADES of experience. I went to his shop for repairs first likely 20 years ago and I think he was long there already. He likely has more experience with O2 sensors than almost everyone on this board combined.

Edit: One local shop quoted me that it could be up to around $300.

 

Walker 16337

 

I drove likely about 100 miles today as well as a couple of quick trips and coming home from Chesapeake after the cat was installed, so I have likely driven 170 miles without and codes. Don't know if it will stay that way but at least looks good at the moment.

 

Updates since that response. No codes in the 10 days since replacing the Cat and my MPG is not at 44.6 mpg. I don't resent my mpg at fill ups but instead let it change slowly. Win the new fuel injectors and cat, I am seeing a lot of 50+ mpg on the bar graphs as well so likely will go up more.

 

If it was going to just be a pile on Kitsune, I did not consider any need to respond.

In my defense, if you google "repair shops doubling cost of parts," you get substantial support for my argument that they do so. Some sources state "Double or more." Maybe they have to charge that to stay in business. I am not too bad at math and the numbers, especially with a labor rate of $105 an hour (recent one I was quoted) don't seem to work but maybe I am forgetting something. If they have to charge that, I cannot afford their labor+cost. I am still forced to do it myself. I also have in the past bought parts and had mechanics put them on.

People who said it was the cat, not the sensor I listened to. Those that suggested that if I end up buying a new O2 sensor, I should get Denso, I also listened to. In the end I end up replacing the cat and ran great for a while until something serious happened with the engine, which honestly just seems bad luck, since I think I checked the oil within the last few days before it happened.

 

I am currently driving the older 2003. Looks more like a Camry or something, not a Prius. The local Toyota dealer wants 300 and change, maybe 360 but might be misremembering the exact amount, for a new battery. They would have to special order it however. There is also no "Out in the world" equivalent. Called another dealer and they want 400 and change. Also have to special order it. I do remember that it was over $100 more than my local wanted. All Toyota dealers seem to charge their own prices. Ended up using a lawn mower battery Hey, it works.