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Service bulletin SF220AB

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id617850
Published by NHTSA2001-04-02
Manufacturer's numberSF220AB
Manufacturer's date2001-01-01
NHTSA componentENGINE AND ENGINE COOLING:ENGINE:GASOLINE

NHTSA's summary

FREIGHTLINER LLC, ON BEHALF OF ITS FREIGHTLINER TRUCKS DIVISION, IS INITIATING FIELD SERVICE CAMPAIGN SF220AB TO MODIFY THE VEHICLES MENTIONED ABOVE. ADDING AN EXHAUST ORIFICE TO THE INLET SIDE OF THE MUFFLER TO CUMMINS B5.9 AND C8.3 NATURAL GAS POWERED ENGINES WILL ALLOW THE ENGINES TO REACH MAXIMUM POTENTIAL POWER. BY INSTALLING THIS ORIFICE, THE EXHAUST BACK PRESSURE IS INCREASED WHICH ALLOWS THE OXYGEN SENSOR TO PROVIDE THE CORRECT INPUT TO THE AIR / FUEL MIXTURE CONTROLLER. THE MODIFICATION CONSISTS OF INSTALLING AN ORIFICE PIPE AND CLAMP. *TT

The document

No address for NHTSA's copy can be built for this communication. Ask the dealer for it by the manufacturer's number.

Components

Engine

Vehicles listed
FREIGHTLINER FLD
FREIGHTLINER FLN

Listing a model year does not mean every vehicle of it is concerned: the document says which.