Torque App and AFR

[cpaul55]

From what i can tell the oxygen sensors on our trucks are narrow band so the typical AFR PID in the Torque App will not read correctly.  Does anyone have the correct PID and formula to correctly read AFR?

[truckguy82]

Most vehicles are narrowband

 

no idea what “pid” means

[CamGTP]

It's not possible because they are narrowband sensors. There is no way to convert narrowband into a real air fuel ratio/Lambda value.

 

Any aftermarket wideband sensor is the only way to read that on these trucks.

 

I don't have that app but if you wanted to read what it's commanding try searching for commanded Lambda, EQ ratio or something similar to that. But that's as far as you'll get, we can read the commanded but not the actual.

[truckguy82]

12 hours ago, CamGTP said:

It's not possible because they are narrowband sensors. There is no way to convert narrowband into a real air fuel ratio/Lambda value.

Huh? It will read the real Afr, it’s just a narrow range.

 

I had an afr gauge hooked up to a narrowband on my turbo civic. I knew where the afr was 95% if the time. It was pretty much only at WOT that it would be rich beyond the scope of the sensor.

 

narrow band just outputs 0-1 volts. You can figure your afr out by simply knowing the volts.

wideband is 0-5 volts

[truckguy82]

Narrowband is just fine for most vehicles.

 

wideband really only helps for tuning, or if you have a highly modified engine that if your afr is not spot on, kaboom.

 

I just looked at my narrow afr and my egt’s to know if I was having an issue. I was only running 10 lbs of boost. If I was running 20+ i would probably have wanted a wideband sensor to monitor.

[CamGTP]

You do you I guess.

 

If you can tell me that .890mv is 12.5 AFR and .930mv is 11.0 AFR on every single car, then I will believe that you can trust narrowband sensors. I've run into too many vehicles where the o2 sensors mv range varies way too much to be trusted.

 

And I'm still not wrong. A narrowband sensor can not tell you air fuel ratio or a real Lambda value. It's only giving a mv data point that is only a guess at what it may or may not be at.

 

 

Think of how much more accurate you could have been if you used a wideband sensor.

[Grumpy Bear]

Cameron isn't wrong on this. Narrow band single sensor systems knows above, on target and below. The wide band two sensor BOSCH set ups that Honda uses will read 7 to 22 AFR. They don't use fuel 'trims'. They read directly and compare to the load tables. I got allot of seat time in Honda Civics. (all 98 or newer) Oh you can get a gauge to read something directional but not accurate past about a half an AFR either way of 14.7.  

[Grumpy Bear]

On 6/11/2020 at 9:36 PM, cpaul55 said:

From what i can tell the oxygen sensors on our trucks are narrow band so the typical AFR PID in the Torque App will not read correctly.  Does anyone have the correct PID and formula to correctly read AFR?

All the PCM PID will give you is the target value not the actual. It doesn't read it to one you can access. Sorry. 

 

What you can do is install a bung and a wide band sensor and gauge if that helps. 

[truckguy82]

22 hours ago, CamGTP said:

You do you I guess.

 

If you can tell me that .890mv is 12.5 AFR and .930mv is 11.0 AFR on every single car, then I will believe that you can trust narrowband sensors. I've run into too many vehicles where the o2 sensors mv range varies way too much to be trusted.

 

And I'm still not wrong. A narrowband sensor can not tell you air fuel ratio or a real Lambda value. It's only giving a mv data point that is only a guess at what it may or may not be at.

 

 

Think of how much more accurate you could have been if you used a wideband sensor.

I dont see how a wideband functions any diiferently than a narrow band as far as accuracy. As far as I know, the wideband has more range, not more accuracy.

[CamGTP]

Here are some video's to help shine some light on why a wideband is a far better sensor than a narrowband. The narrowband sensor can't tell you a real value of air fuel ratio/Lambda, so they are kinda useless outside of closed loop fuel control.

 

If you tuned vehicles or working in that sort of performance shop you'd really know why they are a 100% must for proper tuning.

 

 

 

 

[truckguy82]

I’m well aware they are far better for tuning, i literally said that earlier.

 

I actually did tune with a wideband. I had someone weld in a bung, i tuned it, then I sold it and monitored the afr off the narrowband.

 

I’m only debating the accuracy. I can watch a video on my own, I can also read a book. I’m on a forum because I want to discuss it with humans.

 

Without watching the video, I don’t see why monitoring a narrowband gauge is useless. Clearly auto engineers that know much more than you and I decided a narrowband was good enough to monitor.

 

I even said earlier that it wouldn’t be good enough for a highly modified vehicle.

 

As far as I know, narrowband will accurately tell you if you are slightly above or below stoich, just as accurately as a wideband. The only time a narrowband is inaccurate, is when you exceed the limits.

 

Personally, if I’m running like 7-10 pounds of boost, I’m good with a narrowband for monitoring, not for tuning. I can atleast ensure the gauge is pegged in the rich under boost.

 

It’s not worthless.

 

 

 

 

 

 

 

 

 

 

[CamGTP]

Being pegged rich doesn't tell the whole story though. It's going to say it's rich when it's at 10.5 AFR and if it's at 12.5 AFR.

 

If the vehicle was tuned to have say an AFR of 11.0 for best horsepower/torque but it was starting to lean out to 12.0-12.5 you wouldn't know it because a narrowband is still going to say it's rich. This is where the wideband always being installed would let you know this. You could let out the throttle if it's going lean and possibly prevent internal engine damage. Running a narrowband monitor and a EGT probe is just extra stuff you don't need when the wideband is going to report the instant change in fuel ratio.

 

 

I tune tons of stuff without a wideband but it's because they are stock vehicles and I am not altering the airflow model within the calibration but the second it has a camshaft swap, headers or boost involved it straight to installing a wideband for the most accurate readings.

[Grumpy Bear]

4 hours ago, truckguy82 said:

 

 

I’m only debating the accuracy. I can watch a video on my own, I can also read a book. I’m on a forum because I want to discuss it with humans.

 

Without watching the video, I don’t see why monitoring a narrowband gauge is useless. Clearly auto engineers that know much more than you and I decided a narrowband was good enough to monitor.

 

 

As far as I know, narrowband will accurately tell you if you are slightly above or below stoich, just as accurately as a wideband. The only time a narrowband is inaccurate, is when you exceed the limits.

 

 

 

This is one of those times watching that second video would be worth your while. 

 

Narrow band reads the range of 14.6-14.8. And that accurately only if E-0 gasoline is the fuel. Single Wide band reads 10 to 20 and like I mentioned earlier the piggy backed double wide band Honda was using in 98 reads 7 to 22 AFR

 

 

 

 

[truckguy82]

41 minutes ago, Grumpy Bear said:

This is one of those times watching that second video would be worth your while. 

 

Narrow band reads the range of 14.6-14.8. And that accurately only if E-0 gasoline is the fuel. Single Wide band reads 10 to 20 and like I mentioned earlier the piggy backed double wide band Honda was using in 98 reads 7 to 22 AFR

 

 

 

 

I seriously doubt it’s 14.6-14.8

 

going to research that one

[truckguy82]

Damnit, ok narrowbands are worthless

 

i could have sworn they were atleast 14.2-15.2.

 

So odd my gauge was hardly ever pegged at full lean or full rich. I guess it didn’t a fantastic job at keeping it at stoich in closed loop.

 

I was probably in more danger at part throttle boost at like 5psi, I’m guessing that was still closed loop at stoich.