I installed my autometer O2 gauge last night and when I tested it verses my scan tool the gauge appears to be reading STFT. It was my understanding that the 02 gauge was sort of a volt gauge reading the millivolts the 02 sensor puts out? Right? If this is true then why/how is the gauge reading matching my STFT?

P.S. my 02 volts are at .6xx under normal driving. I dont want to test nitrous until I better understand my STFT verses 02 Volts dilemma.

 

I sure as heck hope your not using a narrow band O2 to tune anything. You'll surely be running wrong because a 1V sensor does not have the resolution nor speed to adjust to constant changes in the A/F.

Unfortunatey I cannot answer your question as to how STFT relates to a narrow band A/F reading. I'm new to the GMC world and am not edumacated in the GM PCM terms yet.

 

A narrow band can be used for tuning if you know what you are doing. Believe it or not people used to tune without the use of O2 gauges all together back in the olden days. But thats not the point.

I am not doing any tuning just scaning. What i dont understand is why my O2 fuel trim matches my gauge but my O2 voltage does not move out of the .600 range

 

well people were tuning with narrow bands because the price of a wideband was cost prohibitive. Now you can get a wideband setup with sensor for under $500. Try and do that 5 years ago.

However what a 1V sensor is good for is to check for stoich operation for part throttle driving. That is about all it's good for. Well that, and the fancy light show.

 

There is no reason for me to buy a $500.oo wide band when I do not have LS1-EDIT or other tuning softwear. I do however have a scantool that tells me that no mater how I drive the O2 millivolts do not move off .6xx. However the O2 sensor fuel trim will move like a "fancy light show".

 

What is the sampling rate of your scantool? Additionally what make/model is your scan tool