Anyone out there have any experience with the electronics on this engine? I have a 2001 Chevy Astro, 4.3L V-6 Vortec, and pretty much the same engine/ECU combination in alot of Chevy's. I have installed a HHOKitsDirect 772 Dual Block HHO kit. I'm pulling 30Amps with no problem and producing lots of HHO gas....tested it myself! Everything is installed to spec.

Where the problems is....my ECU. I can't get it to budge! Here is what I have tried so far:
- Mileage Chip from HHOKits (came with kit, no response, sent it back for EFIE)
- Dual Wideband EFIE (got the wrong one, my engine has narrowband O2's)
- Dual Narrowband EFIE (wired up, could not get O2 sensors to respond and lean out mix)
- Changed all three O2 sensors using Denso's (old ones looked like they were burning good)
- Changed spark plugs (installed PulseStar Irridiums. Awesome plugs!)
- Still no response out of the Narrowband EFIE (sent back for another chip)
- Just got another Mileage Chip, but this one looks identical to a Volo Chip
- Installed, reset, and is working okay
- Installed an Ultra Gauge to monitor emissions system
- Engine is completely tuned and runs good (top of engine rebuilt, new gaskets, new injectors, new plugs, wires, cap/rotor, vacuum hoses, PCV, clean EGR, etc.)
- HHO injection is into the Intake, behind the MAF sensor, about 6" before the throttle body.
- Did a 'hot reset', when everything was at temperature and running hot.

- I did notice that my exhaust pipes (duals) are a bit sooty. Exhaust smells normal, sometimes strong. I don't get that 'ozone smelling' exhaust that everyone talks about.

Ran 500 miles on two fill-ups with this new, current Mileage Chip. Mileage is the same, actually a tad lower. (17.8mpg) HHO is running at 30Amps. My base average mpg is 18.8mpg. I get about 19.5 Hwy and 17 City.

Anyone got any ideas on the OBDII workings of this engine? This can't be this hard to make something happen. I'm producing the HHO, the ECU is overriding everything I do.

Thanks.....