Theoretically, if I jacked up my fuel pressure to say 20psi, wouldn't the O2 sensor just lessen the duty cycle of the injectors, creating no actual increase in power?

 

O2 sensor only functional in closed loop. it will enlean a rich scenerio in CL but only within parameters the ECU will allow and see. excess fuel pressure could put it over the edge and uncorrectable by 02. the increased power may come from enleanment as well as enrichment. depends on underlying tune, WOT is not controlled by 02 sensor(kind of). it is called PE and is factored off of BLM and underlying VE table. I believe adding fuel pressure will cause possible excessivly rich PE and less power and waste petrol(gas).

 

Factory tunes are usually rich, and you'll make more power if you lean it out. If you're not datalogging you would be crazy to go cranking on things like fuel pressure. There is no way to know where you're at or where you are going without logging. For WOT tuning you really need a WB O2 sensor to effectively know whats going on.

 

...and you'd toast your O2 sensor. They don't like rich conditions.

 

Thanks bros