[mwebb]

02 sensors can not see 02
oxygen sensors can not detect oxygen

02 sensors detect combustibles
02 sensors detect combustibles
02 sensors detect combustibles
02 sensors detect combustibles
02 sensors detect combustibles

and
alcohol vapor will not exit the HOT exhaust
it will combust IN the exhaust if it has not already combusted in the combustion chamber .

liquid water will kill the 02 sensor deader than dog poop
liquid water will kill the 02 sensor deader than dog poop
liquid water will kill the 02 sensor deader than dog poop
liquid water will kill the 02 sensor (or AFR sensor) deader than dog poop
when it cracks the thimble because of temperature shock

Originally Posted by ShadeTreeMech

As was mentioned earlier, water injection was useful when pushing an engine to the limit and wanting to keep it there. The water would cool down that which was extremely hot and allow it to keep functioning.

For those of us trying to get from point a to point b, remember that a modern engine is watching the output from the o2 sensor to determine the fuel output and modify the injector cycles to compensate.

Using a fine mist of water (preferably washer fluid, as it is cheap and has a high alcohol content) the washer fluid will exit the exhaust as water and alcohol vapor, NOT as 02 and hydrogen. The water vapor shouldn't be recognized as o2, as it isn't o2 it is water vapor. This should cause the ECU to lean the mixture out, and since a cooling agent is in use, it should prevent damage to the engine from too hot of a combustion cycle.

Using enough water injection will likely decrease power in a naturally aspirated vehicle, but decrease in power = decrease in fuel usage.