So Just as the title says. I swear my 2004 Z knows I am getting ready to sell it, and I already picked up an 08 350Z for the track
So my car just passed 100k and all of a sudden that favorite SES light came on. I hook up my scanner and got code P0031. Replaced the upstream o2 sensor (Bank 1 Sensor 1). Still had problems and returned sensor and got different sensor. First sensor was from "auto parts warehouse" and second sensor was BOSCH sensor from Autozone. Then replaced 15A fuse hoping that fixed it. Still getting SES light and code P0031.

Completely lost for what could be possibly wrong. Never had a simple code like this not go away. Anyone with similar problems or suggestions on how to fix this please!!!! Its too the point to where having my car stolen or simultaneously combust would be a relief.

 

Stick with OEM O2 Sensors. Aftermarket stuff's given me more headaches. Have a look at your sensor wiring. You may be shorting out somewhere.

 

i used an oem sensor and im still having the exact same problem. from what i've seen wires look ok but haven't inspected them further yet. i agree it's def driving me crazy as well.

 

Alright so I took your advice and replaced it with an OEM NTK o2 sensor. NTK part number 24401. Still getting same code and don't know what to do next. Really puzzled here. Bank 1 sensor 1 is the passenger side upstream sensor above the catylitic converter.
Never had something so simple like an o2 sensor give me such a big headache

 

Check your cats

 

That's what I was hoping to not hear how do you check them? Sorry if the question seems stupid

 

you can remove them and look inside to see if the honeycomb has collapsed. thats what happened to one of my aftermarket cats and threw a cel.

 

Id take it to a reputable muffler shop and start there

 

Do you know what code you were getting? I knew that for our cars there is an actual CEL code for a bad cat

 

I'm sorry I dont recall....it happened many years ago.

 

ran into the same problem when I first bought my 08 Z earlier this year- I had the same codes, replaced the sensors, and code persisted. It turned out to be a crack on the OEM cat, near the mounting bracket, left (drivers) side. Replaced both cats with Berk's HFC, codes gone. Code free for 6-months so far

 

Dang that was my worst nightmare. That's what my other friend thinks it is