1999 Tacoma 2WD Base Model 2.4 - Oxygen Sensors Up and Downstream - can't find proper model numbers

Has anyone got experience with this? I have checked everywhere and on the Denso site there are several for up and downstream - not sure which is correct.

Link here

This is one of the first things i am gonna try due to a check engine light coming on last week - they have never been changed. I don't own a meter to tell me a code so I will try these first. Any suggestions>

 

I've needed to find a part number and used Partsouq. Just enter VIN.
Also, I bought a little obd2 tool I think it's BAFX for about 20 bucks and TorquePro app. Inexpensive, doesn't take up much space, and works pretty well.

 

You can get code from sequence of flashes on the check engine light. Check owners manual for directions for that or search here online. 2.4 & 2.7 from ‘95 to ‘01 had cast exhaust manifolds which are prone to crack near the engine block. May want to look for that too before buying parts. First thing is to see what code is causing check engine light. Them attack the problem.