[mondeonz]

AFAIK, cylinders are numbered 1 to 4, looking at the engine from left to right.
However, injectors are numbered in engine firing order, NOT in cylinder order. Hence the confusion.

To make things a bit more confusing, if you have a bar code sticker with 16 digit injector codes on the engine rocker top, the location of the code determines which injector is it for.
P.S. The codes on the sticker are for factory fitted injectors, which might not be the actual injectors currently fitted to the car.

Cylinder 1, Firing Order 1, Injector 1 - Code location on the sticker: Top left
Cylinder 3, Firing Order 2, Injector 2 - Code location on the sticker: Top right
Cylinder 4, Firing Order 3, Injector 3 - Code location on the sticker: Bottom left
Cylinder 2, Firing Order 4, Injector 4 - Code location on the sticker: Bottom right

I'm 99.9% sure this is the way, but someone else can confirm too.