Hi guys, i have an alfa 147 2.0 gasoline with bosch me7.3.1 ecu. I dasabled rear 02 sensor by map because i remove the catalist. Now i want map ecu,but when i do log i see that  the first lambda sensor don't work good and the ecu stay always in open loop mode and don't go in closed loop mode. Now i have dubt. What it's the strategy map for make afr? The ecu follows normal map open loop lamfaw and Lambts or only Lambts or other "protection map"? So if the ecu use normal open loop map i can to set afr by lamfaw or lambts and don't change 02 sensor. Thanks

My problem is the first sensor (pre cat) and non second that i desable d by map.the ecu run in open loop at partial load and i don't know how  it makes afr:  with normal map lafwa lambts, only lambts or other protection map.

But if i If physically detachment the first o2 sensor how thw ecu make afr at midle and high load ? With normal open loop map or protection map?

If i haven't installed primary o2 sensor the ecu run in limp mode?