O2 sensor collywobbles

Yes, another O2 sensor dilemma. First a little background.
I'm new to jeeps as of 10 months ago and decided to start the adventure with a 2006 Wrangler 4.0 in running condition but with many issues - a retirement project if you will.
Amongst other things were O2 sensor PIDs related to Bank2:Sensor2. It mostly ran fine but with low MPGs (10MPG) and frequent rough shifting when cold.
After much reading (and much great info from this forum) I discovered the reliability issues with the later TJ's PCM so bought one from WranglerFix. The OBD2 errors went away as did the rough shifting (still crappy gas mileage). I was happy up until 2 months ago when the OBD2 errors popped up again, this time on sensors 1:1 and 2:2.
I should note when the problem first popped up I replaced all 4 O2 sensors with Walker parts listed on a post here. The OBD2 error & shifting issue was still there until I installed the new PCM.
I check continuity on the O2 cables & looked at OBD2 voltage plots and it seemed sensors 1:1 & 2:2 were responding slowly when the vehicle was first started (sensors slow to warm up?). The heater lines seemed to be connected when checking continuity. I'm not a fan of blindly replacing parts, but the warranty is thin on the PCM so I decided to replace the 2 problem O2 sensors with NTK parts. Problem still there.
Enclosed is a plot of all 4 O2 sensors at start and idle for about 5 min. There are a couple throttle pumps in there as well. I have some ideas for what to do next, but am looking for input from experts as well as wanted to leave a trail of data for any newbs behind me to follow ( I love data).
It does look like the new NTK sensor 1:1 is slow to warm up. Also 2:2 is a little slow. Also interesting is 1:2 does not seem to be riding on the expected 2.5V bias. These are things I will look into next.
Long enough post for now, but am looking forward to any feedback. I'll post progress as I work through this. Thanks.

Yea, I have the older sensors. I'll swap them in to see if they behave any different.

I've done some wire checking, but will do a more thorough check when I get back to it.

After returning from a weekend adventure I started back in on searching for the O2 issues. I wanted to probe the 4 pins of the O2 sensors so I bought an extension cable from amazon and stripped some insulation off each wire to attach my oscilloscope to.

I started with sensor 1:2 to investigate my (False) assumption that the OBD2 data should have been riding on a 2.5V offset.
As can be seen in the image, the Heater signal is clearly working and the Sensor data IS riding on a 2.5V bias. After seeing that I realized the PCM subtracts that bias off when it measures the O2 signal. So this is a working case for comparison. Note the O2 sensor was already warmed up from a previous test so didn't need to come down from 12V like it would in a cold start.

Next I'll take the same measurements with sensor 1:1 which was very slow to warm up.....

Moving on to sensor 1:1 to investigate the slow to warm up issue that caused the P0132 voltage high error.
The data clearly shows no PWM action on the heater pin. This certainly explains why it was slow to heat up.

I inspected the wires and performed a continuity check back to Connector C2 pin 18 and it measured good. I checked for a short to ground and it measured 14.5 ohms which is about right for the heater element. It all looked good so I cleaned the connector, reinstalled and ran the test again. Still no worky.

I didn't check O2 sensor 2:2 which exhibits the same problem but assume it's a similar issue. I contacted Mark at WranglerFix and he said send it in and they will investigate and repair. I wanted to get this all worked out while the PCM was still under warranty and Mark was easy to work with so far.

I have my original PCM which I might play with while I'm waiting, I'm also wondering about the poor gas mileage (10 MPG) and am wondering if the low voltage value on sensor 1:2 is a clue. It's my understanding a low voltage means less O2 or rich. This is after the CAT. Who knows what the PCM does when it detects anomalies in O2 sensor data. Maybe it falls back to some fixed settings that just happen to mean running rich on my jeep? It has been running OK the last couple months (other than poor mileage) with these O2 errors, but for the last couple days it suddenly developed a rough idle when hot (were talking desert hot. We live in the Mojave and it's been 110 F).

As always I look forward to any feedback from the experts out there!

Chris, does anyone have a theory on why the later TJs have more PCM issues than earlier years? A hardware change or buggy firmware to add more emission controls?

After I removed the old PCM and installed the Wrangler Fix PCM I couldn't help myself and opened the case of the old unit. I was able to remove most of the potting goop and looked up the computer chip used in it. It was interesting to see that the flash memory had a 10 year guarantee. Failures would typically be minimal after that but slowly increase with time. I have no idea what was used in the older jeeps. I wonder if a simple "refresh" of the flash memory would get things working for a few more years.

I also noticed a couple capacitors that are likely in need of repair. Heat is a tough environment for capacitors.

It would be nice to know what WranglerFix is doing but I can certainly understand their need to have some trade secrets.

Speaking of heat, when I removed the PCM to ship back to WranglerFix I was surprised how hot it was after sitting for 1.5 hours. Does anybody try to improve the thermals on their PCMs to improve reliability? Fan, shielding, heatsink?

I received my PCM back from WranglerFix. A quick, painless process. I installed it when I got home from work and captured some data. Everything looks great on all four O2 sensors. It started right up and idled smoothly with no CELs.
Jay at WranglerFix tells me they replaced the O2 sensor circuit driver. Below is the data from all 4 sensors. They all warm up quickly, show the heater PWM signal and the upstream sensors even show the pulses from the PCM sweeping the mixture back and forth across the optimum setting. Now to see if the mileage improves.
Thanks for the quick service Mark and Jay @ WranglerFix.

So I've had enough time to run a tank of gas through the jeep and unfortunately not any significant change in gas mileage after getting the O2 sensors working.

I'll start another post on that when I start digging in since it doesn't seem to be related to O2 sensors.

Thanks for the feedback guys. I'm doing some juggling at the moment so I'll dig into suggestions piecemeal.

Closed loop operation: Yes, OBDII reporting closed loop shortly after starting.

I'm using a generic OBDII reader and software which doesn't identify Jeep specific data. Looking at Fuel Trim Bank 1 Sensor 1 and Fuel Trim Bank 2 Sensor 1 I'm seeing both reporting about - (that's minus) 7% when warm at idle. The values bounce a bit. There is an additional value for Fuel Trim Bank 1 Short Term. More noisy but similar average value.

Once things settle down a bit I'll take some more measurements. I have a laser thermometer for that test, but the closed loop indicator more or less triggered as the temp gage was approaching 170-180 deg.

Embarrassedly I have not looked at the plugs yet. It's been on my list.

Another point to add to the confusion, I had an CEL triggered by leaky gas cap. Replaced and CEL self cleared. As I've been burning another tank of gas and the PCM is tuning itself after being replaced it appears the mileage is approaching 12 to 13 mpg from the previous 10 MPG I've seen since I got the jeep a year ago.

Too early for an accurate measurement but maybe an improvement......

Now off to install a new Fridge, Stove and Dish Washer.

Back at it over the weekend. Sorry for the long post. I know most people are just interested in a quick read while sipping their coffee, but maybe this will be helpful to someone pounding their head against the wall with an unsolved problem....

Starting with ItchyDong's suggestions (with some recaps of last post):
-Are you going into closed loop? -> Yes, PCM is entering Closed loop shortly after start up when the temp approaches 170 ish.

-Use a laser thermometer and get the temp right next to the coolant temp sensor when it’s cold and at operating temp. -> Laser thermometer and coolant temp sensor tracked more or less with the coolant sensor reading 10-30 degrees lower than the laser thermometer. I feel this is OK and makes sense.

-Where are your LTFT’s sitting? -> Bank 1 and Bank 2 values bounce around minus 7% when warm at idle. Seems OK. Drops closer to 0 when increasing RPMs.

-With Key on/Engine off, does your MAP sensor read barometric pressure? -> The MAP sensor reports 27.69 in-Hg when key on but not running. Local baro reading was 29.8 in-Hg. Although not a scientific grade sensor, seems good to me. Running & rpm increase dropped the pressure to < 8 in-Hg. Did not try under load, but the MAP seems to be working.

- No sticking calipers? Laster thermometer is handy here too. -> Did not try reading the temperature, but did several slow speed coast to stop runs and it seemed like minimal drag so I don't think there is any significant caliper sticking.

Next up is tr21triton's suggestions. As a foreshadowing keep in mind my embarrassment about not looking at plugs earlier.......

Now for tr21triton's suggestions.
Have you looked at your cats ? -> I visually inspected them when I had things apart fixing Rear Main Seal, head gasket, engine mounts, slip yoke eliminator ........ I did not notice anything odd like buildup or blockage and have not seen any specific OBD2 errors directly related to possible CAT issues. I bought some additive claiming to clean the CAT but have not used it. Could still be something going on here but I'm not sure how to diagnose further.

Spark Plugs? -> Doh. See images. I've owned the jeep for about a year and had it on my list to replace plugs but kept getting side tracked on other issues and fixes. These plugs look terrible with the gaps riding between 0.052 and 0.062 when they should be 0.035. That's on top of the major buildup on them. Also the impedance should be 6K ohm and I'm measuring a wide variance between 10K ohm and 20K ohm.

I replaced the plugs and although it's easy to fool one's self it seems to idle smoother and accelerate better off the start. I just filled the tank and will report back when I've run through it. I'm expecting 40 MPG ;o).

The internets is full of claims about mileage improvements with new plugs. I can believe 10-20% improvement with plugs this bad but would be surprised to see the 50% improvement needed to get the 15 MPGs I'm looking for. This will be a solid data point with only 1 variable changing. Maybe I'll be surprised.