I recently hooked up a HHO Gen (+nnnnn-nnnnn+) & 400hz 30amp pwm to my `99 F-150 with a 4 .6L and 5spd @ 15mpg to the air intake only. I started at 5 amps and around .25-.3 lpm. I lost 1.5 mpg but this may be because I recently reset the comp. I turned it up to 10amps @ about .5 lpm and I just got a 2 mpg gain to 17 mpg. I just upped it agin to 15 amps .6-.75 lpm and I will report the outcome. I haven't altered and senors yet. I would like to see what my gains are before changing any thing and I'm also scared to cook something. If I made changes to any sensors I wouldn't know if it's from the HHO or the sensor mod. The next thing I try after 15 amps will be 20 amps @ 1. lpm and then I want to try a "T" in the vacum. Any suggestions on what vacum to try (i.e PCV) and what sensors to mod. I have a MAF(no MAP), 2 O2's, IAT, CTS, and CHT sensor just to name a few.