Freightliner School Bus Exhaust Parts — FS65, FS65X, and MB45

Auto-jet manufactures Freightliner school bus exhaust parts for FS65, FS65X, and MB45 chassis. Most FS65 configurations use the Mercedes MBE 900 engine — which requires application-specific exhaust components that standard heavy-duty truck parts won't fit.

Freightliner School Bus Exhaust Parts by Chassis and Engine

FS65 with Mercedes MBE 900: application-specific inlet and outlet dimensions. Not a standard HD truck muffler. Using wrong-fit parts creates leak points and back pressure.
FS65 with Cummins ISB: different inlet configuration from MBE 900. Confirm engine before ordering.
FC (Forward Control): different chassis from FS65. Do not cross-reference parts.

Freightliner School Bus Exhaust Parts We Stock

Mufflers — FS65 application-specific for MBE 900 and ISB
Flex pipes — FS65 turbo-to-downpipe connection
Hangers and bracket hardware — MBE 900 and ISB configurations use different bracket locations
Seal clamps — 5-inch connections standard on FS65 muffler inlet

How to Confirm the Right Freightliner Exhaust Part

Chassis (FS65 or FC), engine (MBE 900 or ISB), and model year. FS65 and FC are separate chassis — do not order FS65 parts for FC applications.

Frequently Asked Questions

Can I use a standard heavy-duty truck muffler on a Freightliner FS65?

Not on MBE 900 applications. The Mercedes engine has specific connection dimensions that differ from standard HD truck configurations.