[roadrunner117]

A little history: I brought my car to the dealer two weeks ago complaining of a rough idle right before accelerating from a stop. They replaced the spark plug wires on the back two cylinders closest to the firewall (left and right), so 4 wires total. They also suggested replacing the spark plugs, for $750. I said no thanks to the spark plug change, and went on my merry way. The car drove fine after leaving the dealership, and there was no more rough idle.

Fast forward two weeks later, to this past weekend. I bought new Bosch platinum OEM spark plugs online and started changing them all out. The spark plug wires seemed very straightforward, as the top of each coilpack is labeled "a" and "b", and on the engine right by each spark plug, is also labeled "a" and "b". So I figured, wire "a" goes into spark plug "a", and wire "b" goes into spark plug "b", right? Well I got to the last cylinder closest to the firewall on the driver's side, and noticed that the "a" wire was plugged into the "b" spark plug, and the "b" wire was plugged into the "a" spark plug. These were 2 of the 4 wires that the dealership had changed two weeks ago. I was, like, WTF????? After changing all the plugs, I connected the wires the same way for that cylinder (what appeared to be the wrong way), and the engine started up fine. Drove it for a day, and everything seemed fine. I then convinced myself that there's no way that's right, and switched the wires on that cylinder, so that wire "a" plugged into spark plug "a", and wire "b" plugged into spark plug "b", just like all the rest of the cylinders. Started up the car, and it sounded fine. I then took it for a long drive, and everything seemed fine.

So. . . did the dealer definitely cross the wires on that cylinder, or is there some secret that we don't know about, where the cylinder closest to the firewall on the driver's side needs to be crossed that way? If the dealer crossed the wires, why did it seem to have no effect on the engine?

Sorry for the long post, but I'm now very curious as to what others out there think. Thanks!