My truck has the check engine light on - scan shows that all four O2 sensors are bad. Dealer said he never heard of that before and it can't be accurate. Anyone ever see this before?
Ever hear of this before? All 4 O2 sensor codes being thrown? Lexus dealer said no.
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Eyedaho
SILVER Star
Unless they're all contaminated from something in your exhaust stream that seems really unlikely. How's it running? Any other codes? Losing oil or coolant?
It’s is whats the codes ? Like lean bank 1-2 or Rich bank 1-2 ? Perhaps ?
After reset how long before code reappears?
Then if driving, what conditions are they, load , coasting, steady state … an accelerated speed?
Fast codes, normally unless work has been performed and grounds left loose, fast codes are the Heater circuits, slower codes take 2 trip logic,
That could be a lean or rich condition. Mass airflow contamination can cause lean, vacuum leak, low fuel pressure ect. Rich, purge valve, fuel pressure regulator … ect.
If mixture related look at Fuel adaptives long and short with a scanner. That’s tells you lean / rich right now, and over time.
Just basic trouble shooting… thing to consider
But how does it run? What changes recent ?
Any work performed?
Latest rats / mice / squirrels eat wires can cause odd issues.
All things to consider
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- #4
Truck runs great - no issues at all. No issue getting fuel in. There is a smell back by the gas tank - not gas but something emissions related. But not all the time. Mostly at lower speeds. I cleared the codes and less than 2 miles later the light was back on and the codes were back. I am not a DIY guy so I don't really know how to answer the rest of your questions. Honestly, it is the kind of thing where if I was emissions exempt I would never had the truck looked at.
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- #5
Also, when the light came on about a year ago a new gas capped fixed it. No longer. Tried two different ones.
Ok, if you can get me the codes… ?
Next do you have a live data scanner or just a code reader ?
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She is in the shop - but will get them once the Dx is confirmed.
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- #8
**Update**
Codes were: P0031, 0037, 0051, 0057, 0441, 0442, 0446
Turns out it was corrosion at the junction block connection - they restored heater circuit and purge valve operation and all the codes clear, she passed emissions no problem AND it fixed two other ongoing issues - the steering wheel now retracts AND door locks work with the key fob. Neither worked for months. $700 in labor to fix it all. Dealer gave me a 2023 350 f sport as a loaner so I was happy.
Codes were: P0031, 0037, 0051, 0057, 0441, 0442, 0446
Turns out it was corrosion at the junction block connection - they restored heater circuit and purge valve operation and all the codes clear, she passed emissions no problem AND it fixed two other ongoing issues - the steering wheel now retracts AND door locks work with the key fob. Neither worked for months. $700 in labor to fix it all. Dealer gave me a 2023 350 f sport as a loaner so I was happy.
Fantastic !
