1toofastlt1

iTrader: (4)

Do I need to do anything to my tune for the 2 step? when im on the 2 step my afr reads all the way lean. is this bad? I dont like lean

dville_gt

iTrader: (5)

reads lean because the spark has been cut and the fuel is being pushed into the exhaust without having been burned. since there was no combustion event the oxygen in the cylinder is pushed out as well. since an oxygen sensor doesn't actually read fuel, but rather, oxygen, it see's this added oxygen and reads lean even though it is technically richer due to the unburnt fuel.

1toofastlt1

iTrader: (4)

ok i see. Thanks for the info, it all makes sence now. and I guess a engine cant be lean with out spark. Thanks again.