I'm running a Power Commander 5 on a 2014 SGS with a Stage 1 upgrade. I'm wondering why there are caps called "oxygen optimizers" to put on the exhaust bung sensors. What could this possibly achieve, since they're not hooked up to the ECM or PCV? It's just a dead-end wire from the exhaust port. What is it optimizing? I would think a piece of tape over the loose end would have the same effect! Am I missing something here?

 

Certain Power Commander equipped models require O2 optimizers which plug in to the O2 harness. This is not a thru wire, they have a very specific resistance to prevent the ECM from going into closed loop and also from setting an engine light from the sensors being unplugged.

 

PCV runs open loop. Primitive way to tune EFI closed loop systems IMO.

 

Thanks for the explanation FuelMoto. I guess I didn't understand the wiring when I posted! Now I see the O2 optimizer goes on the harness to the ECM, not the wires to the exhaust. I embarrass myself!