Originally Posted by
ADuff321
Yes lambda 1 will always be equal to stoich. Trying to change or convert units will probably only further confuse the situation since the vehicle is already equipped with widebands from the factory and the pcm really thinks in terms of lambda. It's musc easier to just think in terms of lambda because that takes into account the differences in fuel and ethanol content. Lambda is just the ratio to stioch of what ever particular fuel you are using and its associated stoich afr. The factory has it set to 14.08 because thas the stoich value for gasoline with 10 precent ethanol or E10 as its known, which is most commonly found in the gas pumps across the USA. you can use an external wideband if you like but it's really only going to be like a triple check that the factory ones are working right since you can already cross check them to eachother (and the pcm does this on its own as well).