Hi, just wondering if my primary o2 sensor will work correctly if plugged into the secondary o2 sensor pluggin under the dash? the plugs are the same, just wondering if it will work right and not throw a cel or run funky or anything. car is a 96, running a obd1 ecu, reason for doing this is im installing an aem wideband seperate from the primary narrowband. thanks for any help.

 

The primary bung for the o2 sensor is usually located right on the header downpipe. You need it there for the ecu to read and determine the a/f ratio. The secondary bung for the o2 sensor however usually is located on the catalytic converter. This had nothing to do with the air and fuel mixture of your ecu but it will give you a CEL if its unplugged or if the cat has gone bad. If you plug your primary wire on the secondary o2 sensor bung it will not give your ecu an accurate reading resulting in poor performance and maybe a CEL.

Primary o2 sensor= used for determining a/f mixture ratio. Mandatory!
Secondary o2 sensor= used for determining if your catalytic converter is working or not. Not mandatory for obd1 ecus or jdm obd2 ecus.

Leaving any of these unplugged will give you a CEL and both will affect your performance unless you have an obd1 ecu then it will not look for the secondary o2 sensor.

 

ok thank you very much