First o2 sensor part number?

@05RedTaco O2 sensors measure amount of oxygen entering catalytic converter and exiting catalytic converter and the computer compares the data to determine cat(s) are functioning.
Air/Fuel measure oxygen AND read and adjust fuel to air ratios allowing to diagnose STFT and LTFT (Fuel trim live data) used by the computer to continuously adjust fuel to air ratios.
Like a robo mechanic auto adjusting the screws on a Carburated engine.

 

That is the part# called for if yours is the 99 2.7 right from the Denso Aftermarket.

It would not be the first time some one pulled that plug apart removing the transmission I found a round 4 pin plug on one I was changing .

Best of Luck

 

It is the 9001, I went through this crap not long ago

 

Im curious as to why you sold the

$137 234-9001 Upstream Air Fuel Ratio Oxygen Sensor with 10.6” 4-Wire Harness, for Auto Trans Equipped Vehicles

234-9001 sensor on B/S/T?
I remember that fiasco as well as a few others with missing emissions stickers changing/modifying plugs on sensors from Amazon/fleaBay I hope you solved the exhaust dilemma, suks getting aftermarket parts that aren't quite right.
You still got PermaCEL?

 

Nope

$153 234-9002 Air Fuel Ratio Sensor

234-9002 as per Denso
New # to me

 

While we are on topic, What is the P/N for the replacement nuts and do the Denso parts come with the gaskets?

 

Sensors purchased from Denso do come with gasket. The nuts and studs are m8 x 1.25 I bought SS from ace hardware.

 

I never had one, was trying to get the fuel trims correct but didn’t have a converter so was chasing my tail. I sold the A/F sensor cuz you were correct and mine used an O2 and the loser on EBay wouldn’t take it back. I haven’t gotten around to install the exhaust but have it all (including a cat) I’m looking forward to seeing the trim numbers afterwards. Are you feeling ok? You are normally yelling at me, lol, hardly sympathetic

 

Glad to hear it working out for you.
I'm good. Yelling?
I'm not yelling
THIS IS YELLING

 

Thanks! I bought these:

$13 Micro Trader 12pcs Exhaust Manifold Nuts Head Stud Nut M8 Hex Copper Self Locking Car Parts

https://www.amazon.com/gp/product/B07GJHDLQY/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 on Amazon and they worked perfectly.