Quote Originally Posted by twing View Post
I read this article http://www.pca.state.mn.us/waste/pubs/4_10.pdf and couple of sites about carb cleaner. They say some can evaporate. Maybe those are the oxygen-sensor friendly carb cleaner.
Oxygen sensor friendly carb cleaners are the ones that combust and don't leave a combustion product that can coat the O2 sensor. Since you are spraying it into the intake arm, the stuff that coats the intake arm won't combust (well, hopefully )

The ones that totally evaporate are more expensive. If in doubt, just spray a bit on a tile outside and see if it evaporates. Remember to clean up after so kids/dogs/cats don't lick the stuff.