Let me explain. The fuel sending unit on this truck also has a fuel temperature sensor. Without this information, the truck had the following DTC's (diagnostic trouble codes):
Codes that apply to this issue:
P0183: Fuel Temperature Sensor A Circuit High Input (fuel temperature sensor was missing as it was damaged while installing the new fuel pump last year)
P0463: Fuel Level Sensor Circuit High Input
P0328: Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor) (similar effect, poorer gas mileage because the truck may run less timing advance or spark advanced as this model of truck doesn't have valve timing)
P0420 Catalytic converter inefficiency code for bank 1
P0430 Catalytic converter inefficiency code for bank 2
Check out my diagnosis and understanding article on this topic:
P0420/P0430 Catalytic converter below efficiency
Personal story of almost killing myself a year ago:
(BE SAFE!)
I got stuck under my truck once when I tried adjusting how the truck bed was lifted up by myself. I didn't have the strength to get out from under the bed, but I had to use strength continually to keep from getting crushed as well.
As I kept trying to get leverage to get an old fence post back up and under it I let myself get crushed for a few seconds, feeling my life risking, slipping away, I exploded, using the nearly planned on fear to get the truck bed up and get that board back underneath it!
Don't let the apparent ease in the video of the leaning truck bed tilt bed method fool you. It, like any other raising of a vehicle is DANGEROUS.
This is the truck bed's, tilt or lean method for getting to fuel pumps part 1, and surprisingly, more importantly for my truck's miles per gallon, the fuel temperature sensor.
Spoiler alert for part 2!
With this fault gone, the truck is willing the create LTFT, or long term fuel trims. This is a permanent fuel adjustment for more or less fuel to get the O2 sensor behaving right, which is how much it's adjusted versus what the truck thought it needed to satisfy the O2 sensors, but then it needed to adjust a bit.
As vehicles age or break down, these LTFT's can change a lot and seeing their patterns, they can help find a diagnostic direction.
STFT, or short term fuel trims, are adjustments that are changes on top of the LTFT. They can be additive or take away whatever change the LTFT commanded. STFT are exactly as they sound, they're temporary adjustments, when a certain level of them is needed enough times, LTFT's come in to set a baseline so that STFT can do it's job, which is to make the O2 sensors switch across lean and reach, which helps the catalytic converters last the longest possible, keeping the engine in a range that is safer for all of us. It's our world. Let's take care of it.
Something I've learned since the part 2 video is that my Nissan Frontier has flipped it's roles on it's miles per gallon to something for normal. I was getting freeway MPG in the city and city MPG on the freeway and they've flopped back.
So it'll save me more on trips and less the rest of the time. Oh well, my longer trips cover far more miles than my little city uses in gas.
by AutoBravado
