[Christ]

Originally Posted by Daox

I have a waste spark ignition system.

Several coil packs, right? There should be signal wires for each pack that you can run jumpers from to ground them, stopping the packs from building charge and firing the plugs. It'll stall your engine. This is how older go-karts and stuff are shut off... the shutoff switch grounds the signal to the magneto, so you get no spark. Since you're EFI, it'll still fire the injectors until the engine stops rotating, but you're talking about mL of fuel at that point.

Another route would be an injector kill, but that will probably also show a CEL, although I believe injectors only give intermittent CEL's (it'll go away when you restart).