Finally back doing some chores on the truck tonight. First up was replacing the front O2 sensor. This is the one in front of the cat converter. I'm replacing due to a recurring P0133 code I get here and there.
I ordered a denso from amazon for around $45. It looks slightly different than the stock one but is the model number given by denso as the replacement for my 97 runner. This model is for a 97 ltd 4wd with auto transmission and for the upstream o2 bank. You can search in the reference link below to get the correct model number for your year model, transmission style and what not.
Reference links:
Oxygen Sensors | DENSO Auto Parts
Find My Part | DENSO Auto Parts
Model I ordered, which is now $49:
Amazon.com: Denso 234-4162 Oxygen Sensor: Automotive
New one with box and model number visible:
O2 Sensor location. I'm laying on floor looking up just behind the steering rack and on the passenger side of the transmission. The nuts are 12mm and there is a replaceable seal that comes with the new sensor:
Sensor harness plug location next to sensor and beside transmission:
Old and new side by side:
Plug on replacement is direct plug into factory harness:
Factory harness is up near transmission. You get the plug to come out by inserting a screw driver under the tab visible on the top side of the plug in this picture. The tab has to lift away from the plug to clear the small nub visible on the picture before this one:
I've just finished this project and all told it took about 5 to 10 minutes. I took longer to post this post than the do the actual swap. Hope these posts and pictures help others along the way. Cheers!