Homebrew Cylinder Deactivation
 

I can't do this on Josie, she's carbureted. But my Subie has individual injectors, and a lot of other cars out there do.

Aftermarket power chips are everywhere. Is anyone doing custom programs that would shut down some of the injectors under low-load conditions? I know most of the aftermarket chips are intended to increase power output with longer injector-on times etc, but if the programmers can do that, then surely they can go the other way?

I ask because I rented a new Impala for Thanksgiving that got about 28mpg at 75mph - that's great results for a big car making good time. That big V6 would switch to three cylinders and back again; I never noticed unless I checked the data panel. Imagine what I could get out of a smaller, older - and paid-off! - car if I could just install an aftermarket ECU chip that would shut down cylinders 2&4 at steady-state cruising?

Frank knows it! I think pulling a couple pistons/rods or picking up a spare cam and grinding the lobes off is easier than repositioning the oxygen sensor. Speaking of which, are there any cars that have the Oxygen sensor in one of the runners and not in the manifold/downtube?