Firedome48

Doing a large 50k service over the winter in NJ and had to pull the Cats to get to the water pump. Found the O2 sensors looked a bit tired and thinking about replacing. Since I had to grind off the Cat to muffler hardware I’m afraid of snapping these upon extraction. Any advise would be helpful.
btw, service to include:
water pump
serpentine belt
pulleys
tandem oil pump
fluid flush
Radiator hose replacements.

4Driver4

As a CT native, I’d say those look pretty normal.

fourthirteen

Spray some CLP or PB Blaster, or something similar, on the joint and let it sit overnight…that would help.

Quadcammer

The only thing that works is heating the absolute nuts out of the bung

991Targa4S

Besides heat to the bung or penitent I always treat frozen threads like your tapping new threads.

Start with a sharp jerk but only a small amount.
(If your looking at a clock dial, only turn it 5 min at a time) Just make sure your back off and turn back and fourth the “5 min” worth you just turned. Then “cut another 5 min” of threads and back it off and clean out the threads back and fourth a few times to open up the complete free threads. Keep inching it up and clean out by backing off back and fourth.

997ajk

1)Use heat! Even a portable small torch works well!
2)Cut the wire or 02 off a bit, so you can use a proper socket (27mm - i think) - i find sockets with 02 senor cut outs tend to have some flex
3) you can try impact wrench or a large breaker bar on this

If all of this fails/ drill it out...

Petza914

Once you've soaked it in your favorite penetrating oil, and heated it with a propane torch, get a ratcheting wrench that fits all the way around the nut. If the electric plug is too large to pass through the hole in the ratcheting side of the wrench, then get a flare wrench that will go more of the way around the nut than a regular open end wrench so it gets a better grip on the hex.

Firedome48

All good advise. I will attempt this week. Thanks.

rileyracing1

You don't need to pull the cats to do your WP ?

Firedome48

Too late for that. I’m also replacing tandem oil pump and needed access to back half of engine. Used the rennlist write up and researched. Seems much easier. Also doing an extensive amount of work so it made sense.

rileyracing1

Ahhh .. Well now is the time to do it .... I am also doing some over the winter maintenance . It feels weird doing jobs where you are not in a rush to get last minute parts or things done .

Firedome48

After some persuasion the O2 sensors and Cat bolts have been removed. FYI, the bolts were machined in and needed to be drilled, heated then knocked out. Also replaced the water pump thermostat and a few hoses.

Xios

Nice work. Just replaced the rear O2 bank 1 on mine. Did that yesterday, thankfully got it done without removing anything but the rear wheel.

bschurr

FYI - there is a special socket for O2 sensors that contain a notch on the side to accommodate the wiring. And, always be sure to add anti-seize to the threads of the new O2 sensor when you replace it but be sure not to get any goo on the actual sensor. Sorry if you already knew this but I learned the hard way 20+ years ago on a Wrangler and wanted to share.