Im building a custom with EFI motor and wish to know how (if possible) I could use flamethrowers??

From my understanding flamethrowers work by turning off the spark, and allowing the fuel to flow thru the exhaust where a spark plug iignites the fuel causing the flame throw effect.

now... with EFI..

the O2 sensor would measure a rich mixture and reduce the injector pulses .. so no flame throw effect..

Is it possible to trick the ECM into thinking everything is OK, to allow fuel to be sent into the exhaust for the flame throw trickery??

perhaps mimiciking the O2 sensor signal voltage is the easiest??

any help would be appreicated.
Cheers

Ed