This article describes how to remove and install the caterpillar 320D2 excavator C7.1 engine supplemental air filter
CAT Comm Adapter 3 478-0235 Diagnostics for Caterpillar

1 . Open the left side access door (1)
2. Remove the cover (2).
3. Remove the primary filter element (3).
4. Remove the fine filter element (4)
5. Disconnect the harness assembly (6). Disconnect the hose (5).
2 Connect the wiring harness assembly (6). Connect the hose (5)
.3 Install the fine filter element (4).
4. Install the primary filter element (3).
5. Install the cover (2).
6. Close the left side access door (1)