purchasing the correct O2 sensor?

2005 SR5 V6

I've been battling with the P0430. My mechanic is feeling confident replacing the O2 sensors may solve the problem. I have had a rough few months of repairs. Possibly out of pity, and knowing that I will be back on the regular, he told me on the sly to go out and purchase the part and bring it in and they would take care of it. He didn't give me specifics. I did some research. I'm looking for some confirmation that this:

https://www.autohausaz.com/pn/2344209

is
1. The correct part
2. Is this one? Or is this two? Do I need to buy two of these?
3. Are there any other parts that I should purchase that are necessary for him to do this?

Thanks in advance, and be nice

 

Denso is fine to buy, I don’t know if I’d buy a ‘universal’ one though. OEM P/Ns are 89465-35690 and 89465-35670 I believe by typing your info into a Toyota parts website. I think our 4Runners have 4 total sensors, two upstream and two downstream… does that code tell you which sensors or bank (side) is bad? Replacing an O2 sensor is fairly easy which is why he probably offered to do it for free… just unclip the electrical connector, unscrew old sensor, screw in new sensor and reconnect.

 

Thank you for replying, I apologize for not responding. As I'm sure some of you will understand, I had the pleasure of the lights going out again and not having to think about this for a bit. It is still an issue but something else has started that is now the priority... Stand by for a post