MY23 Mass Air and Lean Codes

Story: Yesterday morning I was heading to work and my truck started hesitating, power would surge, then it leveled out. A few more miles down the road it gave me power reduced, check engine, hybrid malfunction, and all the safety tech disabled warnings. I took it to the dealership and they told me it was bad gas. The computer showed mass air and fuel lean codes so they tested the gas and it “looked bad.” Then they told me I just needed to drive the rest of the gas out (had a quarter tank left). I asked them if it would be better to fill it up and they said I didn’t have to, the truck should be able to handle the bad gas. So I took them at their word. I made it less than a mile down the road before the warnings came back. I managed to roll into a gas station and I filled it up. Then it wouldn’t start at all. Had it towed back to the dealership and I am now waiting until after Labor Day for them to get around to looking into it.

I’m confused that after burning 3/4 of a tank of gas it would finally start having issues. My guess is the fuel filter is clogged or having issues. That or the O2 sensors are bad. The dealership seems like they’re leaning towards just calling it bad gas since that’s not covered under warranty.

Anyone have a similar story or mechanical insight?

 

Toyota doesn’t use fuel filters. It’s just a sump pump type design. The trucks under warranty. If you haven’t modified the intake. Ride it out and see how it goes.

 

Bone stock. Everything is covered under the factory warranty except in the case of bad gas. It doesn’t sound like it to me because of the mass air flow code but I’m far from an expert.

 

So what code did you get? What number?

 

P0171 (Lean Fuel Bank 1 and 2) and P0101 MAF.

 

T-SB-0030-23

 

Probably should’ve gotten a gas sample before adding more gas. This is the 3rd or 4th time hearing bad gas in the last few months here.

 

50 years of driving in the US, Mexico and Western Europe and I've never heard the lazy excuse "bad gas".

 

This and in an area that has had many many inches of rain in recent months. Seems common more
and more.

 

This, read it.

 

Finally got some news on my truck. Apparently it's a bad pcv valve. We'll see I guess.

 

it happens especially with the major oils pulling out of the market long ago, your now left with some stations doing their own compliance and maintenance and poof UST failure and water in the system

we see it often