O2 Sensor

All,

Am i correct in saying O2 sensor reading is not used on wide open throttle on almost all cars ?

O2 Reading is used in cruise range and closed loop / partial throttle?

The reason I ask is a distant friend of mine has de catted his car which has 4 O2 sensor, 2 pre cat and 2 post cat. since removal no light but lots of errors in the info of the ecu.

I am thinking ecu will run the engine rich when reading is same on pre and post during idle / crusing and some people suggested lean. any thoughts on this please?

Thanks

Hello it really depends on the car type make model etc but the can will go into a predefined fuel and ignition curve on most ecus to keep the engine safe

if the 02 sensors have been unplugged