Injector duty cycle
1. If the car was lean would the injector duty cycle try max out to compensate?
2. Can you tell by O2 voltage what the AFR is?
Usually narrowbands are around 850-900 at wot. But they are not the correct thing to tune wot with. They are only best at 14.7 afr or stoich.
Injector duty cycle is usually maxed when out of fuel pump. If they are at 66% and your lean means your tune needs alot of work! Just my .02








