What is the firing order of a 1999 Pontiac Montana mini van?

The 1999 Pontiac Montana used several different engines. To know the firing order, you must specify which engine is in your van. The firing order will be different for each engine. Look for a sticker under the hood or consult your owner's manual to determine the engine's displacement (e.g., 3.1L, 3.4L, etc.). Once you know the engine size, you can then find the specific firing order online through a repair manual or automotive website.