[mwebb]

did you really think that the OEMs have been using AFR sensors since the early 2000 s
and the systems do not have the ability to be in fuel control when leaner than 14.7 to 1 ?

why else would they have gone to the expense and trouble of using AFR sensors in the first place ?



look where NOX peaks , about 16 to 1 , after that you can swag that combustion temp goes down as lean ness goes up as NOX forms at around 2500f and if the system is lean er than 16 to 1 there is plenty of 02 to combine with the N

so
conditions leaner than 16 to1 can not have higher combustion temps than conditions at stoich , 14.7 to 1