This means that the spark plugs fire in that sequence, starting with cylinder #1 and ending with cylinder #6.
Here's a breakdown of the firing order:
* Cylinder 1: Front of the engine, driver's side
* Cylinder 2: Front of the engine, passenger side
* Cylinder 3: Rear of the engine, driver's side
* Cylinder 4: Rear of the engine, passenger side
* Cylinder 5: Front of the engine, passenger side
* Cylinder 6: Front of the engine, driver's side
Important Note: This firing order applies to most 2002 Pontiac Bonnevilles with the 3800 engine. However, it's always best to consult your owner's manual or a reliable repair manual for your specific vehicle model to confirm the correct firing order.