Years ago at a Route 66 Classsic, Joe Sharp had a device that he connected to the tailpipe and could quickly tell if the mixture was correct and adjust the ECU knob as needed. My car ran fine for years until I messed up and failed to document the position before moving the knob while working on another issue.
I have a Gaston CO gauge (www.gunson.co.uk/product/G4125 ) that I thought would allow me to set this, but I've used it on both my D-Jet 914 and the L-Jet in my sons bus without good results. It seems no matter how I adjust things, the CO never settles down or gets down to an acceptable level so that I can be certain that I have things set right.
What do you all use so that you can be sure you have the ECU set right?