O2 sensor question...

[67SS509]

What is the difference between the front O2 sensor and the rear one. I know they do different jobs but will they interchange if you change the connectors. What I really want to know is can the rear one be used in the front?

[joecar]

Front O2 sensors: close the loop so the PCM can trim the AFR to stoichiometric (14.7 for gasoline/petrol).

Rear O2 sensors: PCM uses these to measure efficiency of catalytic converter operation.

Typically the front and rear sensors are or can be the same part number...
but sometimes there may be a difference such as a longer cable or a different connector (flat vs square), and the number of wires (3 or 4 wire).

If the connectors are different, you may swap connectors, but you have to be sure to get them right -> need a wiring diagram to identify each pin... do not cut/solder, but do use a MetriPack terminal pick (outlined in red in the pic).