ScanGauge Air/Fuel Ratio Accuracy?

[Trojan4x4]

I've been getting really crappy gas miledge...which prompted to punch in a fuel ratio code I've found on here. However it never goes over 12...which has me wonder if there's something very wrong or it's not very accurate . Do any of you guys use scangauge to measure fuel ratio?

 

[phattyduck]

Its not the Scangauge so much as the ECU and sensor. Mine sits right at 14.7 +/- a bit for most engine operating loads. It isn't very useful to me once I saw/knew that, so I have my Scangauge show other things (coolant temp, trans temp, air intake temp and trip MGP).

What year is your 4R? What X-gauge code did you use?

-Charlie

 

[19963.4lsr5]

Are you in closed loop?


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[Trojan4x4]

Are you in closed loop?


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I'm not sure. What's the difference? I'll check on scan gauge
EDIT : it says closed loop

Its not the Scangauge so much as the ECU and sensor. Mine sits right at 14.7 +/- a bit for most engine operating loads. It isn't very useful to me once I saw/knew that, so I have my Scangauge show other things (coolant temp, trans temp, air intake temp and trip MGP).

What year is your 4R? What X-gauge code did you use?

-Charlie

1999


Air to Fuel Ratio (True Air to Fuel ratio)
TXD: 07E02144
RXF: 04614544
RXD: 2808
MTH: 05BE00800000
NAM: A/F

Mine moves around and only gets to 12 after an hour to driving or so . And maybe 10 under acceleration

 

[phattyduck]

In my notes I have:

TXD: 686AF10124
RXF: 04414524
RXD: 2808
MTH: 05B900800000

or:

TXD: 686AF10114
RXF: 04410514
RXD: 2808
MTH: 05B905000000

I'm not near my truck, or I'd check what is actually in my Scangauge.

-Charlie

 

[gamefreakgc]

I'm not sure. What's the difference? I'll check on scan gauge
EDIT : it says closed loop



1999


Air to Fuel Ratio (True Air to Fuel ratio)
TXD: 07E02144
RXF: 04614544
RXD: 2808
MTH: 05BE00800000
NAM: A/F

Mine moves around and only gets to 12 after an hour to driving or so . And maybe 10 under acceleration

If you don't have a A/F (wideband) sensor and the older O2 (narrowband) sensor, the only way to get your A/F is with installing a second aftermarket wideband. Does you 99 have two cats or one? If it has one, it has a narrowband and that A/F ratio on the scangauge can be ignored, it will not read correctly.

 

[Trojan4x4]

In my notes I have:

TXD: 686AF10124
RXF: 04414524
RXD: 2808
MTH: 05B900800000

or:

TXD: 686AF10114
RXF: 04410514
RXD: 2808
MTH: 05B905000000

I'm not near my truck, or I'd check what is actually in my Scangauge.

-Charlie

Let me put both in my scan gauge and I'll see if they read different.

If you don't have a A/F (wideband) sensor and the older O2 (narrowband) sensor, the only way to get your A/F is with installing a second aftermarket wideband. Does you 99 have two cats or one? If it has one, it has a narrowband and that A/F ratio on the scangauge can be ignored, it will not read correctly.

Mine is in Cali and it has 2 cats

 

[muellernautique]

after i get out of class, i will go punch those in my scanguage and see what sort of numbers i am getting. didn't know there was an xgauge code for afr.

 

[Cree]

Having an air fuel ratio readout on a stock vehicle is pretty well pointless. The ECU is going to set your fuel trims to maintain as close to stoic as possible, which is 14.7. When you start adding boost or playing with fuel trims in a tune then you need to keep an eye on it but otherwise the computer is going to do what it needs to do to keep it there. I truly don't see the point of it on a low performance motor like ours. If your truck is truly that far out of spec you should have an Associated code stored in the ECU somewhere.

 

[Trojan4x4]

Having an air fuel ratio readout on a stock vehicle is pretty well pointless. The ECU is going to set your fuel trims to maintain as close to stoic as possible, which is 14.7. When you start adding boost or playing with fuel trims in a tune then you need to keep an eye on it but otherwise the computer is going to do what it needs to do to keep it there. I truly don't see the point of it on a low performance motor like ours. If your truck is truly that far out of spec you should have an Associated code stored in the ECU somewhere.

Ever since my snorkel install and my cherry bomb I have a feeling that I'm running rich. I won't know if it's just a feeling or I am actually running rich without monitoring fuel trims

 

[Cree]

Ever since my snorkel install and my cherry bomb I have a feeling that I'm running rich. I won't know if it's just a feeling or I am actually running rich without monitoring fuel trims

If anything, you should be running leaner. increased intake flow plus reduced back pressure.....

In any case, what [MENTION=115347]gamefreakgc[/MENTION] said is spot on. Without a wideband you're not getting an accurate read.