I was told that a DEFI air fuel gauge is not a true air fuel gauge or doesn't read it how it should. Would anyone be so kind to tell me if this is true or false? I have this gauge in my car but it's not hooked up anymore due to this from my rebuild. Do I need a air fuel gauge such as a AEM?

 

if its attached to a wideband sensor, 4.2 or 4.9 and reads afr/lambda(sp?) then its wideband/afr gauge. im not sure i understand what youre asking. a wideband is a wideband so long as the sensor is legit. it just comes down to brand and features that differentiates them.

 

A general A/f gauge is not enough by itself to accurately read the Air to fuel ratio. A standard o2 sensor reads 0-1v. A wideband o2 sensor reads 0-5v. That's quite a difference. To get your Air to fuel gauge reading the actual (correct) a/f ratio, it MUST have that input from the wideband o2 sensor (0-5v). Otherwise it's just a fancy light show.

 

I don't even think Defi makes an AF gauge right now. It does look like the older gauge they had was a narrowband gauge that used the stock O2 sensor.

You do NOT want a narrowband gauge. That's way old technology and they are pretty useless. Back then widebands were like $1500 and no one had one so we had to make do. Now they are dirt cheap and very accurate.

Dale