Which O2 sensors to replace?

[01CuHed]

I have a 2001 Jeep Wrangler Sport I bought new back in 2001 and approaching 71,000 miles. I have never had a check engine light for O2 sensor but feel age alone they probably should be replaced? Do I only need to change out the 2 pre-cat O2 sensors for performance and fuel efficiency?

 

[L J]

Do I only need to change out the 2 pre-cat O2 sensors for performance and fuel efficiency?

Yes. MOPAR or NTK sensors.

 

[01CuHed]

Thanks LJ that confirms what I was thinking and I know to only trust NTK or NGK O2 sensors. I guess the only time you have to replace the 2 post-cat O2 sensors is when you have catalytic converter problem.?

 

[Jerry Bransford]

Thanks LJ that confirms what I was thinking and I know to only trust NTK or NGK O2 sensors. I guess the only time you have to replace the 2 post-cat O2 sensors is when you have catalytic converter problem.?

Yes on all that. You can add the Mopar O2 sensors to the list of acceptable replacements, all three of which are made by NTK.

 

[01CuHed]

Thanks Jerry...now it's time to start spraying them down with Liquid Wrench. Ha!

 

[Jerry Bransford]

Thanks Jerry...now it's time to start spraying them down with Liquid Wrench. Ha!

And use only a conventional 7/8" socket and/or 7/8" box-end wrench to remove them. Don't try to remove them with a slotted O2 sensor socket which is too weak from its slot to hold together while removing a stuck O2 sensor. Those special slotted O2 sockets are only for installing new O2 sensors, the slot being for the wiring. Cut the wiring off the old O2 sensors before removing them.

 

[01CuHed]

Thanks again Jerry for the heads-up tip on how to remove old O2 sensors. I was thinking I might need that special socket now I know to save my money :>)

 

[L J]

Thanks again Jerry for the heads-up tip on how to remove old O2 sensors. I was thinking I might need that special socket now I know to save my money :>)

I've only used an open end wrench and accessed the sensors from the driver side wheel well.

 

[Jerry Bransford]

Thanks again Jerry for the heads-up tip on how to remove old O2 sensors. I was thinking I might need that special socket now I know to save my money :>)

You may need the slotted socket to install the new O2 sensors. I'd buy one but save the receipt and don't remove it from its packaging so you can return it or have it if you can't get the new sensors fully installed without it.

 

[C.J. Roberts]

You may need the slotted socket to install the new O2 sensors. I'd buy one but save the receipt and don't remove it from its packaging so you can return it or have it if you can't get the new sensors fully installed without it.

I got a set with the Autozone tool rental plan. Pay for it, use it, return it for your money back. Unless you make a living changing the things out, I see no reason to buy a set.