Clean the throttle body where the blade comes close to the throat of the throttle body. It usually gets sludge built up there and affects idle. Also, clean the IAC or replace it.
As for lean afr, does the car run good? Does it have good power? If so, then don't worry about it. Widebands can be fooled by many things, especially being placed too far away from the exhaust port.
As for lean afr, does the car run good? Does it have good power? If so, then don't worry about it. Widebands can be fooled by many things, especially being placed too far away from the exhaust port.