"For about the same price you can get a narrowband 02 sensor and a cheapo gauge."

This was exactly what I had in mind to help me with that 3mm hex adjustment in my lambda-less 79 kjet. I set it by ear at idle, after becoming familiar with the subtle sound changes the later LH cars make while correcting around stoich, but still was not satisfied with fuel consumption rate.

Frustrating part was finding a place to put the sensor, after cabling up a heated model to be used with a VTVM. The test port on the headpipe is too small; the EGR tube thread in the manifold is different. I'd have to weld on a bung just to use this, or make some kind of tailpipe insert/extension.

How do you do it cheaply in the djet, presuming it has no sensor bung?
--
Art Benstein near Baltimore