Washed the car yesterday (exterior only, not the engine bay) A few hours later, I try to start the car and it won't start. It turns over, but it sounds/feels like only a few cylinders are firing. Not enough to keep it going.

I checked the forums and found a post that suggested it might be a blown fuse, specifically the fuse that controls the ignition coils (http://www.renntech.org/forums/index..._1#entry127527). Unfortunately, I checked all of the fuses in the fuse box in the engine compartment and all of them look okay.

Any suggestions on what I should check next?

I tried to run my Innova OBDII scanner, but it didn't find any codes (maybe this particular scanner doesn't work with the Cayenne).

By the way, I should mention that the car has had a rough idle. The previous owner said that he replaced the coils and plugs, but I'm not so sure about that. Could a cracked or melted coil(s) cause the no-start issue?

Thanks for your help.