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Discussion Starter · #1 ·
I'm a longtime lurker who just got an '03 with about 100k on it. Almost entirely stock, as far as I can tell, though the intake is CL. I already love this thing and don't know why I waited so long to get one.

I'm a bit of a novice and didn't notice when I bought it, but the wideband AFR gauge looks like it's running lean. It usually sits at right around 16.0 at idle and easy cruising, occasionally spikes to 16.9 (which I imagine is the upper bound for the gauge). At WOT I see 12.0 or so, though I haven't pushed it much yet. From what the internet tells me this is very lean and could be an issue so I'm hesitant to really push it.

I tuned it with a diablosport using their 93 octane canned tune, but that doesn't seem to have changed much of anything. Otherwise the truck runs great with no CEL or other issues. There is a very slight clicking noise that I don't think is a problem. Never any overheating, and almost looks like it runs a bit cold on the gauge.

My questions:
1. Is an AFR for idle/cruise at 16.0 and WOT at 12.0 dangerously lean?
2. Is it possible that the wideband sensor/gauge isn't set up right or is otherwise inaccurate? Can I verify that? I'm using the Torque app with a bluetooth OBD2 connector, but it doesn't seem to pick up either the commanded or actual AFR, so I'm not sure that data is even coming through the OBD2 port.
3. If I am running dangerously lean, what can I investigate to fix it? I already checked/cleaned the MAF sensor, since that was quick and easy, but doesn't seem to have made an impact.

Thanks in advance - this community has been an awesome resource.

Tom
 

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Tipton Co. Garbage Truck
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1. on paper 12.0 is about right. in reality with our trucks I think 10.5-11.0 is what most folks shoot for at w.o.t.
2. doubt the gauge is messed up (see #3).
3. canned tunes are garbage. get a sct and a custom tune from a lightning tuner

my .02
 

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10 second street truck
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1. on paper 12.0 is about right. in reality with our trucks I think 10.5-11.0 is what most folks shoot for at w.o.t.
2. doubt the gauge is messed up (see #3).
3. canned tunes are garbage. get a sct and a custom tune from a lightning tuner

my .02
Mid to low 11s. 10s is to rich
 

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The "lean" at idle or cruising when you're not into boost isn't a problem.

I thought canned tunes tended to run more on the rich side than lean? I had a canned tune in my '04 when I bought it and that thing ran 10:1 under boost.

Which wideband are you running? Is it just an LED strip, or do you have the ability to datalog it at all and tell exactly what it is under WOT? You mentioned 12.0 and 16.0 so I'm guessing you have more than just LED's going on.
-Matt
 

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Some of the widebands out there do require a re-calibration every now and then - the Innovate widebands have that feature built into them to do that with a push button switch or a jumper. Also, if the sensor starts going bad, it can read lean.

The factory calibration in the tune files calls for 12:1 AFR at WOT - we drop that down to around 11.5:1 for safety with added boost / timing.

If the truck is stock, the high AFR at idle could easily be a leaking EGR / vacuum lines, etc, but unless the OP is getting a CEL with P0171 / P0174 codes, I doubt there's a problem except with the wideband.

Bird

ps. the 'clicking' noise could be a loose spark plug - might be wise to check all of them before one ejects itself.
 

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Discussion Starter · #6 ·
The wideband I have is this one, which gives a numerical output:
http://www.autometer.com/2-1-16-wideband-a-f-w-sensor-ultra-lite.html
Looking through the manual for the wideband, I don't see any way to calibrate it, so I'm not sure that's even an option.

As for logging, I tried to get Torque to log it over the OBD port but it doesn't seem to come through. I'll try to use the diablosport device to log, or get the recall on the wideband to see what my max/min AFR is.

No codes for a lean condition, but the longterm fuel trim does look a bit high (averages under 5%, maxes out at 20%).
 

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The wideband I have is this one, which gives a 1numerical output:
http://www.autometer.com/2-1-16-wideband-a-f-w-sensor-ultra-lite.html
Looking through the manual for the wideband, I don't see any way to calibrate it, so I'm not sure that's even an option.

As for logging, I tried to get Torque to log it over the OBD port but it doesn't seem to come through. I'll try to use the diablosport device to log, or get the recall on the wideband to see what my max/min AFR is.

No codes for a lean condition, but the longterm fuel trim does look a bit high (averages under 5%, maxes out at 20%).
1. Nope - that one self calibrates

2. AFR isn't used in the control - won't show up in ODB. You'll have to take the 0-5v output of the WB and bring it into the datalogging device to be able to read it in conjunction with the rest of the parameters.

3. Is the 20% at idle and low cruise? If so, it could be in conjunction with the high AFR you're reading - could be something to look into.

When was the last time the fuel filter chaged out?

Bird
 

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10 SECOND CLUB!
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1. I would adjust the gauge to max out at 20 instead of 16 if that's currently the max.
2. The gauge is self calibrating.
3. Check for vacuum leak
 
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