Yes, that's right! The only reason we pull the plugs is because in essence, it affords us a kind of direct access and ability to concentrate the fluid. Nothing gets sucked out or wasted in that particular process like it does on the running engine process. Then of course you put the plugs and wires back, and it should be ready to go 30 min. later. I think you're really going to be pleased with the results you get. I know a lot of guys get sticker shock when they buy their first can, but you've gotta know you're getting it all back in mileage at the financial level, and then the renewed drivability is just the icing on that cake! Let us know what you think!