Hi, first time poster, long time viewer of the page for all things f150. I currently own and drive daily a 2010 Ford F150.

So recently I've had a check engine light come on. The truck itself was found to be running perfectly fine without any odd issues. Upon getting the code scanned it was found that the fuel was "too lean" which was resulting in the error code. We figured that it was either an O2 sensor itself or probably just bad gas as Okanagan fuel is well known to be the worst of the worst. As such I changed gas stations and the next time I filled I put in supreme (91) fuel as a test. After a few days the check engine light turned off and stayed off.

So as luck would have it the next fill up there is a brand new gas station in my area and I figured I'd give them a try but go back to regular (87). New tanks, new filters, new pump - seems like the best test scenario for what should be the most "optimal" regular fuel in this area. After a few days no light however the day I went on a longerish trip and came home the next start that stupid light came on again.

Has anyone else ever experienced anything like this? Is this a symptom of just winter regular fuel being treated differently and my truck just doesn't like it? Or is it time to switch out what still, to me, seems like a properly functioning 02 sensor?

 

Possible other (though not limited to) factors causing too lean ...Engine? *Rather than playing 20 questions ...

HINT/TIP: Put your -complete- vehicle information (year, model, cab, trim, engine, wheelbase, _x4 drive, mileage, modifications, etc., etc.) in your signature -OR- provide it in your posting(s).
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Signatures seem challenging to get to through the mobile version of the site, I had put those details into my profile description but I see now it's not easily available. See below.

2010 F150, extended cab with the 6,6" box, XL, 4.6L 3V, 4x4, 131,XXX KM,

Modifications: cold air intake, remote start, 2" leveling kit, rims

My gut says it's not an air filter problem because again the issue disappeared completely upon changing the fuel. I use the same logic with the vacuum suspicion. I never run the fuel too low as a rule of thumb because as stated in my posting the fuel in my area is well known to be of poorer quality. I usually will refill my tank with around 200 km remaining, I have gone as low as 100km remaining. I've never seen the "low fuel" light before. Exhaust leak could be a possibility given I typically drive very short distances and with that in mind I know exhaust rot is more common so I will need to look into that for sure.

Any other suggestions would be greatly appreciated. I do find it strange though still that I've had success by simply running a higher octane fuel but I suppose that could be just compensating/covering up the real problem.