O2 sensors

I bought new sensors, upstream and downstream. When I went to replace the up stream one, one side looked like it should have nuts on it but didn’t. The other side was rusted and couldn’t tell what it was even supposed to look like. I thought I would get some advice on here before I tore into it and couldn’t get it back together. The downstream sensor is not even there. It looks like the place that replaced my muffler went straight out of the catalytic converter and did not use a pipe that had a place for the sensor. Any advise?

 

You know you can just buy the mid pipe with the correct mount....
they sell everywhere.....might be couple days order from Azone, Oreilys, Advanced, ect...

Exhaust Pipe Walker 52452 | eBay




most likely your rear flange on your cat is compromised, so gonna have to it cut/welded in anyways.....

 

This is cheaper if you can do the work yourself.

https://www.ebay.com/itm/202192070389?fits=Make:Toyota

 

So, I broke down and took it to a mechanic and they cut a hole in the pipe for the downstream sensor and welded the flange that came with the sensor onto the pipe. They replaced the upstream sensor as well. Now I’m getting a 420 code . Catalytic efficiency or something like that. I believe that code was there before they did the sensor replacement. As I understand it there are two converters…they suggest a test where they run up the rpms. Any advice…would it be cheaper to just replace both converters and be done with it? Can I drive with this code and get crappy mileage or will it do further damage and or breakdown? Thanks again!

 

420 can relate to exhaust leak, I'll check that first. Start the truck and feeling with your hands around the cat and sensor, making sure to not directly touch the pipe.

 

Soapy water while the exhaust is still cold at start up...
the flanges and sensor mount are notorious for hard to find leaks.

Very unlikely to find em just by feel...

 

Would bet it’s an exhaust leak from a bad weld. That just happened to me when I had a guy repair my rusted exhaust behind the rear cat. Once I got the leak sealed up my 420 code went away. Confirm no leak before replacing cats.

 

https://www.tacomaworld.com/threads/burned-out-my-catalytic-converters.809754/#post-29210577