Originally Posted by
Thunderball
I'm running a 772 in my Chevy Astro 4.3L. I originally had the mileage chip, but sent it back. I tried two versions of the EFIE's without any luck. I also replaced my O2 sensors so that they were all new and operating at the same rates. Mine had 200k miles on them.
I now just installed a new Mileage Chip, which looks exactly like the Volo Chip. Not sure if its the HHO one or a performance one. Ran a 1/2 tanks of gas today and it looks like my mileage dropped or remained the same. I did a Hot Reset of the chip and will try again. I'm also going to let it alone for about a week, where I'll put about 1k miles on it, and see what happens.
My exhaust still smells a bit rich, so something is not adjusted right. For you...if you use an EFIE, you'll need to tap into your Upstream O2 sensors, and hope that when you adjust them, your fuel mixture will change. If that doesn't work, you may have to add a chip for your MAP and/or MAF sensors.
Just make sure you keep good records of what you're doing and also the mileages that you are getting. I'm now keeping a log book to also show the new adjustments and additions to the HHO system.
Good Luck.