Hey guys, first I'd like to thank you all for reading and possibly helping me with my truck and yes here I go with another LEAN CODE question. I have looked up and down on every thread and every post and I have learned so much but I must say I have yet to find the issue with my truck.
I have an '08 xlt crewcab 4.6l auto 2wd. I bought it about a month ago for a great price and I have been fixing all of its little issues. The only thing I have not been able to fix is the damn Lean Code I am getting, so here it is.
When I am driving it drives great, the issue is when I get to a stop. The truck starts to have a rough idle sometimes seems as if its going to stall. This hard idle or misfire doesn't happen all the time but when it does, which is often, it happens as I am coming to a stop.
The code scanner OBD2 gives me P2197 02 Sensor Signal Stuck Lean Bank 2 Sensor 1.
I have done the following.
-Replaced O2 Sensor - Twice, Thought the first one was damaged.
-Replaced PCV Valve
-Replaced Fuel Filter
-Cleaned Throttle Body
-Cleaned and checked MAF Sensor
-Checked for Vacuum leaks - Found None
-Did the old screwdriver to injector and they all tick tick tick perfectly
-Checked the wires and connector for the O2 and they look great

Here is the Live Readings of OBD2.
FUELSYS1 CL -- I've seen say
FUELSYS2 N/A - This must be an issue
LOAD_PCT(%) 32.2
SHRTFT1 (%) -3.1
LONGFT1 (%) 1.6
SHRTFT2 (%) -3.1
LONGFT2 (%) 1.6 -- Confirms to me that it's not a vacuum leak
MAP (kPa) 36
RPM (/MIN) 672
MAF (g/s) 5.55
02B1S1 (V) 0.63
SHRTFB1S1 (%) -1.6
02B1S2 (V) 0.630
02B2S1 (V) 0.000 -- THE ONE WITH ISSUE, it moves sometimes but rarely, the max I've seen it up to is 0.100
SHRTFB2S1 (%) 10 -- I'VE SEEN IT GO UP TO 59.4 and stay there
02B2S2 (V) 0.720I took it to a mechanic who connected it to a big scanner, the only thing he said was, its running Lean its your Fuel Filter. Charged me $120 and sent me on my way. Never again! I need to do this myself, I need help and any help will be greatly appreciated!
THANK YOU!

 

Not conclusive by it's self, but in conjunction with the rest I agree with you as follows.

Your O2B2S1 reading is just about certainly an electrical issue. The design of the O2 circuit is that a current limited 'Bias' voltage is supplied to the 'sense' side of the O2 sensing element - this voltage is seen and measured by the PCM computer's Analog to Digital converter. The other side of the sensing element goes to ground. When the sensor 'smells' NO oxygen - it is high resistance or acts like an open switch. So voltage on the sense line is equal to the bias voltage ( 1.0 volt. Generally about 0.9 v). When the O2 sensor 'smells' oxygen - it conducts current to ground (ie closes the switch / becomes low resistance) and the current flow pulls the voltage down to around 0.1 volts.

It is IMPOSSIBLE for a good, proper functioning O2 sensor to pull the Bias Voltage all the way to ground - ZERO volts. That is because the sensing element always will have a small amount of resistance, even when it is activated by smelling pure oxygen. THUS, since you have a reading of ABSOLUTE ZERO on that sensor, you either have an internally SHORTED O2 sensor (but you have already switched it out), OR you have an 'OPEN' circuit in the sense conductor between the PCM and O2 sensor - that includes possibly the wire pin connector at the PCM, OR you could have a SHORT TO GROUND in the sense conductor between the PCM and the O2 sensor, OR it could possibly (but doubtfully) an electronic defect in the PCM.

I doubt the PCM is bad because it is the same A/D converter that measures voltage for both bank O2 sensors.

Your SHRTFB2S1 confirms. The PCM thiinks the O2 smells excess oxygen and hopes to burn some of it up by adding fuel (+ fuel trim).

TEST the integrity of the wiring. That wire runs close to Exhause Manifold and things across the back of intake manifold. Use a volt ohm meter and check the sensor -to-PCM wiring.

 

Lean code is possibly a vacuum leak which is why it runs poorly at idle. Have you tried performing a smoke test on the intake system? Forget guessing at why the codes are what they are,... perform the test to eliminate it specifically. As for the 02 sensors I agree, check the harness and make sure it has no issues including poor repairs.

 

One important clue - that points away from possible vacuum leak. O2 sensors are essentially "semi-conductors" in design, that 'turn on' or become conductive when they smell oxygen. The sense wire is sourced with a 1.0 volt reference voltage, and the sensor pulls that 'toward ground' when it is activated by presence of oxygen. The clue here is that it is "IMPOSSIBLE" for a properly working semi-conductor to pull a reference voltage ALL THE WAY to ground. The absolute lowest normal reading - in pure oxygen - would be 0.1 volt across the internal substrate junction.

The OP's freeze frame data indicates the snapshot voltage reading was absolute zero, an impossibility unless the O2 sensor's internal junction is shorted out or the circuit wiring is shorted to ground, or the reference voltage wiring is OPEN.

I would remove that condition first. Then check for vacuum leaks if indicated.

 

Thank you so much for this reply, after reading this comment I went back and I checked the cables more in detail. After a few days I found the culprit. One of the four cables that runs from the O2 to the computer was touching the back of the engine and grounding the signal. It was almost impossible to find. I only came across it because I decided to pull head cover off to change the gaskets since I had a small oil leak. By doing this, I had less obstructions and I was able to lay on top of the engine to follow the cable down the back of the block. At first glance, the cable looked great but as soon as I turned it to the other side, the back of the engine had graced it and burned through the plastic cover and caused the cables to touch the block and mess with the signal. I am adding a picture here, hopefully you guys can see it. I cut the plastic wrap for a better view of it all. But here you can see how small it was and how it could of been missed. Something so small yet such a pain in the *****.

 

Many Thanks @InsurewithJonal . I Hope many others click 'Like' too - since I can only do it once.

Reporting back a successful find and fix is equally (if not more) helpful to others than all the guidance / suggestions forum members can make from afar without being there.

 

I agree, many other posts I read only showed the problem and suggestions but no solutions. That was one of the reasons why I kept doing different things to the truck trying to find the issue. Even the mechanics I took the truck to, had no idea what it was and would charge me to change random parts thinking it was the issue.

I am by no means a mechanic and even though I have some basic understanding when it comes to engines I am still learning. I will definitely be doing more research for future repairs and I will try to avoid the mechanic shops from now on if I can, I am not saying that they are all bad but I hated spending hundreds for something small that didn't fix the issue and I could of changed myself. Can you believe they charged me $120 to change the fuel filter and another $110 for Vacuum leak check. Then when it was not fixed he said well its the Intake and wanted to charge me $450 to change it, not including the part. Took it to another mechanic shop who charged me $75 to "Diagnose the Issue" and said it was the catalytic converter and wanted to charge me $350. NOPE never again. LIVE AND LEARN

Again, thank you so much for helping me!