I also have an elmscan interface with Scantool software, it's OK for getting information on emmisions related engine components such as the lambda sensor but doesn't read all the erro codes on my VW and doesn't allow you to change anything. I found it too limiting although it should be fairly genereic across a wide range of cars.
STeve
>> What is the best (cheapest) PC-based OBD2 scantool anyone can
> >> recommend that also performs vehicle diagnostic tests (things like
> >> actuator control, open/close valves etc etc)? The vehicle in
> >> question is Isuzu Trooper 98 (VPW
> >
> > Check into a used OTC Monitor 400 Enhanced (not the 4000E, that's a
> > different animal)
> > plus a software cartridge that covers the 1998 imports you can get > > these off Ebay
> > pretty cheap. And example is:
> >
>
> Thanks for tons of info! That Isuzu actually uses GMs VPW protocol, so I
> suspect GM module will do. This is a whole new realm for me... I actually
> bit the bullet and ordered Elmscan's OBD interface, usable both with
> Scantool.net and Digimoto software. What I still do not quite understand is
> whether the OBD interface is generic and theoretically allows for engine
> control (just nobody has hacked the proprietary protocols yet), or does
> tools like OTCs have another way to tap into ECM?
>
> Peter
>
>