ACDelco 22787277 DEF Tank Filler Cap Diesel Exhaust Fluid Emission Reduction

The ACDelco 22787277 is a Genuine GM Parts Diesel Exhaust Fluid (DEF) Tank Filler Cap, designed to seal the Selective Catalytic Reduction (SCR) emission reduction fluid reservoir on equipped diesel vehicles. As a genuine OEM replacement part, it meets the same fit, form, and function standards as the original cap installed at the factory.

Diesel Exhaust Fluid (DEF) systems require a properly sealed filler cap to prevent contamination of the urea-based fluid, which is critical to the SCR system's ability to reduce harmful NOx emissions. A damaged or missing filler cap can allow moisture and debris to enter the tank, potentially causing system faults and failed emissions tests.

Key Features:

• Genuine ACDelco OEM replacement part — not aftermarket
• Designed for DEF (Diesel Exhaust Fluid / AdBlue) emission reduction fluid tanks
• Provides a secure, contamination-resistant seal
• Ensures proper SCR system function and emissions compliance
• Direct OEM fit — no modifications required
• Meets original GM engineering specifications

Replacing a worn or damaged DEF filler cap with a genuine ACDelco part helps maintain the integrity of your vehicle's emissions control system and keeps your diesel running in compliance with EPA regulations.