I've been wondering about Volo chips for some time, myself. I've heard reports all over the place, but most negative ones that I've investigated, it didn't seem like they really gave them a chance.
So, I decided to do a test of my own. My wife has a 2005 Kia Spectra with a 2L engine and is fully computer controlled. I ordered a chip for it. I used one of my old test cells that will output up to 2.5 liters and is fairly efficient. I installed the system about a week ago.
But, the Volo chip wouldn't turn on properly. Only one of the status LEDs would light, and it blinked constantly. After a couple of phone calls to the factory with try this and try that, they determined my unit must be defective. A replacement is on the way.
I'll let everyone know more once it arrives and I've had a chance to test it.
Steve
1991 Plymouth Acclaim 3L V6.
1 dry cells with nineteen 6"x8" 316L ss plates, driven by constant current PWM set at 35 amps (13.3V at PWM). 28% KOH electrolyte. Total measured output 2.5 lpm. Mileage went from 18 to 26 mpg, all city driving (44% increase). EFIE set at .370 and I still need to play with ignition timing.