sssgtr, you're right, one coil does the intake side, the other does the exhaust side. I know the plugs on the intake side run all the time, as for the exaust side, I'm not 100% sure. I was under the impression that they both run all the time. But, the two coils have thier own output from the ECU, so the can be controlled independantly. Whether they are or not, I'm not sure. I'll do some investigating when I get a chance.