Ford Focus Service Manual: Intake Air Distribution and Filtering

The air intake system consists of the following:

• Air Cleaner (ACL)
• ACL element
• Mass Air Flow (MAF) sensor
• ACL outlet pipe

The air intake system:

• cleans intake air with an ACL element.
• measures airflow with a MAF sensor.

The ACL contains an ACL element made of treated, pleated paper. A new ACL element must be installed periodically as scheduled. Engine performance and fuel economy are adversely affected when maximum restriction of the ACL element is reached.