I just installed a Autometer A/F Ratio gauge, which was a bitch to install and I have a question. I know that they are not calibrated right or something for our trucks, so is it normal then for the gauge I have to jump all over the place??? It starts out at lean, then jumps from rich to lean all the time. There are four 02 sensors that I could find and I tried two of them and they all did the same. I was just wondering if the bouncing around is what is common with this type of gauge???

 

That is normal but after you reach a certain RPM for awhile, a continuous minute or so, your air/fuel ratio should "settle" out, and maintain within a certain range. Like, so to say, lean, normal, or rich.

Hope this helps

 

That is what the gauge should do, but I believe on our trucks since they have more than one o2 sensor they make the a/f gauge read funny unless you have a certian kind that is made for our trucks. Just want to make sure I have it right.

 

Sorry,

I wasn't aware of that, but thanks for the insight. I had no idea and as soon as I decide on what other gauge I want in my truck besides the air/fuel, I was going to install mine.

I will try to keep with the info posted here so I will know more when I do my install.

Just out of curiousity, which O2 sensor did you plug in to?

 

I used the first one, then tried the second also. With both the gauge bounced all over the place. I have been told that the AF Gauge on our trucks are really useless.

 

As long as you bought an AF ratio gauge for a narrow band O2 sensor, there is no calibration issue.

So if this is an AutoMeter A/F ratio gauge, then it is made to work with the stock ( Bosch ) O2 sensor that the PCM uses.

The A/F is going to be all over the place which driving. Even if you get on a flat strech of highway with the cruise on, the LEDs will move around a bit. This is due to the A/F level is always changing.

The only time is is steady state, is when you are WOT.
When the TPS is greater the 80% the EPA rules no longer apply, and the DMAP ( no feedback needed ) is used for the tune on the truck. It should go rich on mild or stock tune. The engine is breaking just about every EPA rule, but this is how the EPA has it. Under TPS < 80% follow the guidelines for less polution and good mpg, above 80% TPS free for all.

With the narrow band O2 sensor, it is useful for seeing if you need to get to a dyno and get a wideband O2 data to correct a tune problem on your chip. Beyond that, it has the pretty light thing going for it.

No special calibration needed. If you get the O2 sensor that they see as an assy for your gauge, it is just another narrow band O2 sensor. If you spent ~ 1,000.00 on your A/F then you should have gotten a wide band O2 sensor ( more accurate over the range ).

 

HI!... You should of got a better A/F gauge like the NORDSKOG unit. It's analog. Here's a pic :

http://www.intellitronix.com/images/D70140s.jpg
http://www.intellitronix.com/d70140.html

 

Thanks for the info. The only reason I am using the Autometer gauge is that I got it off another vehicle I have and I didn't want to buy a new gauge when I had a perfectly good one.

 

As long as the O2 sensor is in good shape and newer, it should provide a close reading. O2 sensors operate from 0 to 1 volt, each led of the gauge reads .200 milivolts.

If the 10th led lights is .5 of a volt(1/2 volt or 5oo milivolts) this is the 14.7 to 1 ratio the EEC is trying to achieve. .7/10's of a volt is an 11:1 ratio( good for supercharged applications), and would light the 14th led. The more voltage the richer the A/F ratio.
The light movement is normal, because the EEC is always correcting, trying to get the .5 volts.

Older O2 sensors may not operate within a full span of 1 volt, and may only run .5 of a volt sweep. At some point it will trigger a MIL. , when it gets enough out of range.

 

I know the gauge is suppose to move normally, but it jumps from the bottom to middle with the throttle and it is not suppose to do that.

 

I guess it depends on what you are doing when you put the throttle down.

Say your are driving along ( TPS < 80% ) and chop the throttle, the A/F will go to the bottom of the range, and then when you put your foot back in it ( again TPS < 80% ) it will pick back up to yellow range maybe a bit green depending on how quick you took TPS up, and then drop back off again to the normal range of yellow towards red.

If you want to see what is up, with the engine cold, start the truck. The inital reading is on the bottom of the scale, and then it will jump to green for abit, then start cycling. Al this without touching the pedal.

If you want, I can take a short video clip of mine, and email it to you.

Steve

 

That sounds about what mine does. I start the truck up, it jumps into green, then goes into the orange(yellow) for a little bit. Then after about a min. it wil go from red up to orange and then just jumps up and down from red to the middle every few secs. If that is what yours does then I guess mine is right.