They require a 7/8" wrench. Cut the wire off the old sensor and use a BIG wrench with a long handle to break it free. It's pretty guaranteed it'll be in there tight! Then you can use a slotted O2 socket available at your auto parts store to install the replacement. Those slotted sockets aren't strong enough to remove a seized O2 sensor, they can flex and bend open. The slot is for the wiring of the new O2 sensor to pass through.
Underneath the front pre-catalytic converter.
I doubt you'll be able to get the old O2 sensor out with that particular tool. See my above post.
Thanks Jerry, I just read it. I probably would have tried using it to remove the old sensor.
Thanks for the quick reply Jerry. Yes on the NTK and yes on the front lower sensor. I only get the code after about 30 miles and always at a speed of around 60-65 on the highway. The Jeep runs very good, so no symptoms other than the engine light. Also, not sure if this has anything to do with it or not, but I did use a can of the throttle body cleaner into the intake while the jeep was idling and about a third of the can manipulating the throttle. It idled a little rough prior to that after staring it back up after being parked from driving for 5-10 minutes. Problem with idle resolved. Started seeing the code after that. May not be related but thought I would mention it just in case. Thanks again for the help.
Thanks, I could pretty much say the same thing as you did there. Only replacing the cats proved to be the cure for the repeated errant bad O2 sensor codes. I haven't had an O2 sensor code in the several years since both precats were replaced.
