I run Regular with 10% ethanol in my 2019 Versa and I have no issues.

 

Not possible.

The fuel can and will vary wildly from 10% and can even change at one station in a day.

You can't carry premix gasohol for long distances or time periods. Exxon tried and it cost them hundreds of millions of dollars. It is usually mixed in the local area to be more stable and the mix is never the same. Here in Texas the new car dealers had to begin to test the fuel quality when at times they get a LOT of warranty claims for ethanol fuel system damages in new cars so they could start cutting warranty repairs. Hundreds of them. The tests showed wild variance from almost no ethanol to amounts sometimes topping 20% and the latter situation much more common. There were several news stories on it a couple years ago. Higher ethanol % is more profit to fuel makers and why they go that way.

Now that the number is at 15% in many places the numbers will get worse, crime being the big payer it is.

If Nissan O2s are combo narrow and wide band then you already have your update...........wide band is it.

 

I have been monitoring the fueling for weeks now with the above mentioned scanner and I'm confused, to some extent. I'm familiar with some of the terms and how they relate to fueling. Some I don't understand or, maybe, those are just more useless than others. Maybe Nissan meant it to be this way, or Foxwell did! I should also mention that my scanner offers 39 different line items to observe and it's AC/DC (Bi directional) also.

The list below is everything my scanner can tell me about the fueling, except the last line item which I almost find funny.

1) Fuel system A status.
2) Fuel system B status.
3) Short Term Fuel Trim - Bank 1.
4) Long Term Fuel Trim - Bank 1.
5) Short Term Fuel Trim - Bank 1 - Sensor 2.
6) Oxygen sensor output voltage Bank 1 - Sensor 1.
7) Oxygen sensor output voltage Bank 1 - Sensor 2.
8) Equivalence ratio (LAMBDA) Bank 1 - Sensor 1.
9) Fuel/Air commanded equivalence ratio.
10) Type of fuel currently being utilized by the vehicle.

Admittedly, I'm still learning about the Nissan programming but all of this information seems like too much sometimes. Some of the numbers/functions just don't add up when compared with another.

Here's what I know or have some understanding of:
1) Function of Open Loop or Closed Loop. Displayed as "CL" and "OL-Drive".
2) Apparently this data line is in a wave format that my scanner can not interpret. I came to this conclusion while reading in the service manual, regarding the trouble shooting of the upstream O2 sensor.
3, 4, 5) Got 'em..... I think.
6, 7) I'm coming to grip with these and how they correlate with fueling and A/F ratio. Unfortunately, there's not much info on these.
8) Pretty self explanatory. Even tho this is a narrow band sensor, it's range seems to go further than I'm used to seeing for narrow band.
9) This one has me stumped! When I know the fuel HAS TO BE going rich, this number goes above 1.
10) My scanner tells me that there is GASOLINE in the tank.... imagine THAT!

Which of these, or combination thereof, should I REALLY concern myself with? I'm looking for advice from the more experienced Nissan mechanics/owners/drivers/tuners/etc.

One item I don't see on my scanner is injector pulse width! Does anyone else have a scanner that can display "pulse width"? Well, I no sooner typed this when I remembered that my scanner has a different diagnostic group dedicated to NISSAN, not just OBD2. The injector pulse width is addressed in THAT section but not in OBD2 diagnostics. Also, there are 80 line items available in THAT section! Geeeeeesssss....

Any and all comments are welcomed, even if I should put the scanner down and just drive the car!

Cheers,

Larry

 

You should put the scanner down and drive the car. That's what I do with my 2019 Versa and I don't have any fuel issues. I make sure to offset stop and go city driving with highway driving.

 

3 and 4 are important. As is the cyclic rate of both O2 S1 and 2 which I don't see there at all. The problem I have with Nissan is finding the correct sampling rate to read that off the O2s, I use Torque and they do not give good direction on it at all and you have to mess with it to get good readings. I have an older Harrison R&D reader buried somewhere that can auto read and get the correct sampling but I haven't dug it out of the pile lately. It is narrow only and reads the correct action of the O2s holding on stoic about 4.5v or close and the sensor 2 floats around much slower almost stopped as compared to S1. I pretty much need nothing else but those 4 things. Got a third cheapie reader too and it reads same as the R&D one does.

 

amc49, I'm not seeing this "cyclic rate" you speak of, anywhere within my scanner. I presume you are referring to how quick and/or how far, each direction, the sensors swing. I could probably estimate the time within the datalog frame count, ~ 1sec/frame. Thoughts?

Torque? My scanner doesn't display a torque value in either OBD2 mode or NISSAN mode. I do have, within the OBD2 diagnostics, two LOAD time lines, Calculated Load Value or Absolute Load Value. I suppose torque could be calculated. I've been utilizing the CLV for a guide to alert me as to when the other sensors should be indicating a rich condition. Since the A/F sensor is narrow of nature, I'm leaning on the voltage reading from the same sensor for more accuracy. This stems back to the 420 issue in trying to eliminate fueling as the cause. If the fueling is right then something else is/could be contributing to the cause, like oil or coolant. I'm not seeing any loss in either of those but who knows how much would be required. Since the engine has >221k on it, the PCV came to mind. I'm toying with thought of installing a catch can/filter in that line. Any thoughts on that? I read an old post where you schooled someone on PCV, a couple of years back (humorous). I'm probably grasping at straws, as my grandmother used to say.....

While trying to locate a torque value timeline, I did discover a few parameters (within the NISSAN scan area) that REALLY have me stumped! MAYBE they would shed some light on torque or totally irrevelent. They go like this:
Malprvl
Malprvu
Tprvl
Tprvu
Usrvl
Usrvu

I've googled this stuff and get everything from RV sales to how to replace the blow off valve on my hot water heater. Nothing! Perhaps you may be familiar.

Thanks for your time,

Larry

 

Torque is a commonly used OBD2 scanner software not a torque reading.

'...how quick and/or how far, each direction, the sensors swing.'

Yes. When you hit the correct frame count the sensor 1 will be showing the actual swing high and low past stoic, buffered to slow it down of course, your eye cannot follow the actual swings in reality and why knowing realtime rich or lean at that very millisecond is worthless. My Harrison shows that cyclic swing fine but the Torque software the other scanner uses just gets close to the correct frame rate, the cyclic shows up but not exactly as it should, the frame rate choice is not big enough to finetune it to get a real good view. If you get sensor 1 to cycle well then sensor 2 will show how really slow it moves in comparison to sensor 1.

Use the long (LTFT) and short fuel trims to determine overall rich/lean.