PULLING MY HAIR OVER A P0301 code!!

[PBandJs_PPV]

Update:

Yesterday, the fuel gauge just randomly started working again so obviously there's a loose connection somewhere.

Also, and this sounds REALLY dumb but, I JUST NOW actually looked at the gas cap. I hadn't noticed that fuel requirement and warning. I've just been pumping low grade unleaded from Sam's.
Is this affecting anything?

 

[j91z28d1]

87 should be OK but since you have an issue, if you have a e85 station, you might try some and see how it goes.


on that note do you have a scanner that can read alcohol percentage? these flex trucks use the o2 sensors to try and guess the alcohol % so you can use e85. it more volume than gas to run right. some times the ecm math messed up and thinks you're running E when you're running not making them run super rich. a decent scanner can read what the ecm thinks is in the tank, and if not correct you can reset it.

 

[Fless]

You may use regular gas (87 octane or higher) or E85 (85% ethanol, not available everywhere), or combinations of both mixed. You have a Flex Fuel vehicle, unless the fuel filler cap was changed by mistake. What is the 8th digit of your VIN?

 

[PBandJs_PPV]

87 should be OK but since you have an issue, if you have a e85 station, you might try some and see how it goes.


on that note do you have a scanner that can read alcohol percentage? these flex trucks use the o2 sensors to try and guess the alcohol % so you can use e85. it more volume than gas to run right. some times the ecm math messed up and thinks you're running E when you're running not making them run super rich. a decent scanner can read what the ecm thinks is in the tank, and if not correct you can reset it.

Another curiosity is that the OBD port is hot sometimes. Even with the truck off, I can sometimes connect to the OBD reader and the truck although, as it's off, there aren't any readings obviously. Unless I am truly losing my mind over this.
The 8th digit is a 0

 

[PBandJs_PPV]

87 should be OK but since you have an issue, if you have a e85 station, you might try some and see how it goes.


on that note do you have a scanner that can read alcohol percentage? these flex trucks use the o2 sensors to try and guess the alcohol % so you can use e85. it more volume than gas to run right. some times the ecm math messed up and thinks you're running E when you're running not making them run super rich. a decent scanner can read what the ecm thinks is in the tank, and if not correct you can reset it.

 

[Fless]

Another curiosity is that the OBD port is hot sometimes. Even with the truck off, I can sometimes connect to the OBD reader and the truck although, as it's off, there aren't any readings obviously. Unless I am truly losing my mind over this.
The 8th digit is a 0

So, the LMG, flex fuel.

 

[dkad260]

I've just been pumping low grade unleaded from Sam's.
Is this affecting anything?

The yellow gas cap indicates you can also use E85 if you choose, not a requirement.

However, if not a flex fuel vehicle this could be an issue as the engine requires much more fuel when using E85, the injector flow rate is increased. I doubt this is the problem though but yes, double check your VIN.

 

[Rick Fazz]

Another curiosity is that the OBD port is hot sometimes. Even with the truck off, I can sometimes connect to the OBD reader and the truck although, as it's off, there aren't any readings obviously. Unless I am truly losing my mind over this.
The 8th digit is a 0

Pin 16 should always have B+, required by OBDII standards. You can check with a test light or volt meter.

I've seen pushrods bend when traction is lost. Pull valve cover.
Have you done a visual inspection of wires and hoses from the rear? Sounds to me like a bunch of things started at once,
I would be looking for a common cause.

Fuel gauge sending units are a common problem, on mine once the level goes below 1/4 tank it stops working.

 

[PBandJs_PPV]

OBD Data Dump 01

 

[PBandJs_PPV]

Video

VID_20250517_124728591.mp4

drive.google.com