Joes readings are 100% for where they are at, he is reading the correct AFR at the tailpipe. Put your wideband gauge at your tailpipe and you'll probably come very close to matching his readings. I sort of wish I had an extra wideband gauge to proove/disprove this for people.
Because I was doubting my wideband a few years ago I even went and sold my almost new AEM Wideband and bought an Innovate LC-1, which is known to be a little more accurate and allow free air calibration. The net result there was no differences in my wideband readings between aem and innovate and still Joe's readings were off.
Its not his meter, its just the readings at tailpipe vs at the header.
Because I was doubting my wideband a few years ago I even went and sold my almost new AEM Wideband and bought an Innovate LC-1, which is known to be a little more accurate and allow free air calibration. The net result there was no differences in my wideband readings between aem and innovate and still Joe's readings were off.
Its not his meter, its just the readings at tailpipe vs at the header.