2001 Elantra owner here
Don't know about your car
But my car, the O2 sensor was a bear to get out
I tried the O2 sensor wrench ... failed
I tried it with cheater bar ... failed (broke the O2 wrench)
I tried to remove it with a plumber's pipe wrench ... failed
I tried using propane to heat it up and pipe wrench ... failed
Finally I took it in to a garage and paid fifty dollars to remove the darn thing
Oxy-acetylene torch and pipe wrench, they got it out (20 minutes)
The O2 sensor looked like it had no threads
This is wear and tear of living in the salt belt.
Got a thread chaser to fix the threads on the pipe and put in the new O2 sensor
I never want to do that again

Good luck to you

 

The factory don't use enough, if any, thread dope on these. It can be a southern car and have the same issues with being stubborn. We just heat them cherry red and spray with a little water and they come right out. On real bad ones you may have to repair or replace the bungy.

 

When i replaced mine on my Accent this summer the threads stayed in the pipe. You will need a tapping, not chasing, M18x1.25 thread cutter. Most are just thread chasers and will not start. I had to use a 3/8" NPT pipe tap to get some threads started for the thread chaser.


Fixed my P0420 though. That and a O2 extender.

 

Why are you replacing the sensor? PO420 code? How many miles on the clock?

 

I had to relocate the upstream sensor to accommodate a custom header and it was a pain to get out so I think I'm ready for that part.

Its throwing code for bank 1 sensor 2. I forget the code number though. 58000 miles. I would just take it to the dealership but they will find a reason to not cover it and charge me. Not a fan of the dealerships around here and since I just finished my catback exhaust a couple weeks ago they have plenty of things to blame the failure.

 

Knowing the code goes a long way in solving the problem.

 

I don't need help solving the problem. I asked a simple question on where the connector is located to save me a little time when the part gets here.

 

It's only a foot or so up the sensor. The plug will be attached to either the frame or sheet metal with a taped on plastic tab.

 

BTW if the code is for the cat the sensor is probably not going to help. The post cat sensor should have very little activity during normal operation. It will usually read low (lean) as the cat stores O2 when converting well. When it degrades it doesn't store O2 and the sensor will start reading like the front sensor and that will flag the dreaded PO420 cat efficiency code.

 

Thanks srb. That's what it looked like I just wanted to make sure I wasn't missing something. My sensor will be here today. I'll try to post some pics to help the next guy out when I'm finished.

 

The connector for the downstream o2 is located on the passenger side under the middle console closest to the firewall. There is a small panel that comes off and it's right there. I was worried it might be more buried than it actually was. Overall it only took about half an hour to replace.