The firing order for the 2.2L Ecotec engine is 1-3-4-2.
This means the spark plugs fire in the following sequence:
* Cylinder 1
* Cylinder 3
* Cylinder 4
* Cylinder 2
Important Note: This firing order might not be applicable to all 2.2L Ecotec engines. There are some variations depending on the year and specific model. Always consult your owner's manual or a reliable repair manual for accurate information specific to your vehicle.