BridgePrt

I would greatly appreciate help with my check engine light issue on my 2008 LS 460L with 130K miles. This type of issue is new to me though I'm pretty good with computers and fixing things.

Data is from BlueDriver reader.
The LiveData (see csv file) shows ShortTerm and LongTermFuelTrim Bank1 is normal at idle and gets very excessive held at 3000 RPM and I've read this denotes that it's not likely a vacuum or bad air issue.
The FreezeFrame data happened while going down the highway at 60mph and took quite a while to trigger since last reset. It looks like problem is truly specific to bank1.
I did clean the MassAirFlow sensors prior to this recent trigger. (side note, though I am confused why there is 2 MAF sensors but BlueDriver only shows one possible MAF reading?)
The Live data showed O2 voltages mostly near 0.9 most of the time for both banks 1 and 2 (which I was expecting more change, especially with each press of pedal). Which I was hoping for a clear sign of an issue, but it seems I didn't get a clear sign ?
And also for the Live data, after several rpm increases, it took 3 or 4 cycles of high rpm to get the O2 sensor voltages to do anything significant (note blue and green dips), but again, it didn't seem to have a logical pattern that I know how to read. Note the red chart is rpm and the blue and green dips don't really relate much to red.
And finally note the high short and long term fuel trim patterns at bottom of image or within csv file.




So, given this seems very specific to bank1, and not at idle, what other test data or scenarios should I research, and what would you suggest be my first component to replace, and second component if needed.

Thank you very much for any help.

P0171 System Too Lean Bank 1
P2195 O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 1

Freeze Frame Report
02 DTC that caused freeze frame data Trouble Code P0171 triggered Freeze Frame. Code Def - System Too Lean Bank 1
03 Fuel System Status System A: Closed loop, but fault with at least one oxygen sensor - may be using single oxygen sensor for fuel control (Bank 1 or Bank 2) System B: Closed loop - using all oxygen sensor(s) as feedback for fuel control
04 Calculated Engine Load Value 97.3 %
05 Engine Coolant Temperature 85 °C, 185 °F
06 Short Term Fuel Trim Bank 1 11.7 %
07 Long Term Fuel Trim Bank 1 32.0 %
08 Short Term Fuel Trim Bank 2 3.1 %
09 Long Term Fuel Trim Bank 2 3.1 %
0C Engine RPM 1593 rpm
0D Vehicle Speed 100 km/h, 62 MPH
0E Timing Advance for #1 cylinder -2.5 °
0F Intake Air Temperature 8 °C, 46 °F
10 Mass Air Flow Rate 53.96 g/s, 7.14 lb/min
11 Absolute Throttle Position 56.9 %
15 O2 Bank 1 - Sensor 2 - Short Term Fuel Trim 99.2 %
15 O2 Bank 1 - Sensor 2 - Oxygen Sensor Voltage 0.995 V
19 O2 Bank 2 Sensor 2 (Bank 3 Sensor 2) Short Term Fuel Trim 99.2 %
19 O2 Bank 2 Sensor 2 (Bank 3 Sensor 2) Oxygen Sensor Voltage 0.820 V
1F Run Time Since Engine Start 1093 seconds
23 Fuel Rail Pressure 9650 kPa, 1400 PSI
24 Wide Range O2S: Bank 1 - Sensor 1 - Equivalence Ratio 1.011 λ
24 Wide Range O2S: Bank 1 - Sensor 1 - Voltage 3.495 V
28 Wide Range O2S: Bank 2(3) - Sensor 1(1) - Equivalence Ratio0.991 λ
28 Wide Range O2S: Bank 2(3) - Sensor 1(1) - Voltage 3.241 V
2E Commanded Evaporative Purge 0.0 %
30 # of Warm-ups Since Codes Cleared 6 #
31 Distance Traveled Since Codes Cleared 364 km, 226 mile
33 Barometric Pressure 97 kPa, 29 inHg
34 Wide Range O2S: Bank 1 - Sensor 1 - Current 0.121 mA
34 Wide Range O2S: Bank 1 - Sensor 1 - Equivalence Ratio 1.011 λ
38 Wide Range O2S: Bank 2 - Sensor 1 - Current -0.035 mA
38 Wide Range O2S: Bank 2 - Sensor 1 - Equivalence Ratio 0.991 λ
3C Catalyst Temperature Bank 1 - Sensor 1 714.8 °C, 1318.6 °F
3D Catalyst Temperature Bank 2 - Sensor 1 714.8 °C, 1318.6 °F
3E Catalyst Temperature Bank 1 - Sensor 2 596.1 °C, 1105.0 °F
3F Catalyst Temperature Bank 2 - Sensor 2 596.1 °C, 1105.0 °F
42 Control Module Voltage 13.632 V
43 Absolute Load Value 74.5 %
44 Commanded Equivalence Ratio 0.990 λ
45 Relative Throttle Position 40.4 %
47 Absolute Throttle Position B 98.8 %
49 Accelerator Pedal Position D 30.6 %
4A Accelerator Pedal Position E 46.3 %
4C Commanded Throttle Actuator 56.9 %
4E Time since Trouble Codes Cleared 316 minutes
53 Absolute Evap System Vapor Pressure 97.630 kPa, 391.948 inH2O

swfla

iTrader: (1)

I think you'll find Techstream software more helpful as it's Lexus/Toyota specific.

BridgePrt

Thank you for responding. I ended up driving the car an hour watching live data on my phone and eventually I could see a pattern of B1S1 voltage not always matching B2S1 in times it was most likely to have matched. It was only off by .5 volts but after replacing the AF sensor all is good. I actually replaced the MAF and O2 sensors first as they were easy but it didn't help. Then I saw the fuel pump seals were leaking pretty bad so ended up resealing the fuel pumps, coils, new spark plugs, valve cover gaskets. I've never worked on a car that was such a pain to work on. I cut the AF sensor wires and soldered the wires, heat shrink tubed and taped as there was no way I was going to lower my motor or other crazy stuff to replace sensor 1. Then when I took my valve cover off, I saw that some oil-change employee must have slammed an oil fill tool into my engine and broke a piece of plastic off from the oil fill tube. It made me sick. Who knows when it happened, it could have happened anytime in the last 12 years. It might be floating in my oil pan. And the last time my wife got the oil changed, they let her drive off 2 quarts low. I guess I have to always change my own oil.

Cape600L

"AF Sensors"? I am trying to figure out what that abbreviation is for. Can you explain? Thanks, and glad you fixed it.

Cavedog

Swap the sensors and see if problem moves.

BridgePrt

Air Fuel sensor, or some call Pre Cat sensor. Denso part 234-9052 is bank1 (driver side) and 234-9058 is bank2 other side. Though left right likely does not matter if you plan on cutting the wire and soldering in the new sensor. Soldering was pretty tough too, not as bad as lowering the engine though) super cramped space to solder and wear a face shield if you don't want hot solder in your eye or face.