[Code of Federal Regulations]
[Title 49, Volume 4]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR393.83]

[Page 1094]
 
                        TITLE 49--TRANSPORTATION
 
        CHAPTER III--FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION,
                      DEPARTMENT OF TRANSPORTATION
 
PART 393--PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION--Table of Contents
 
             Subpart G--Miscellaneous Parts and Accessories
 
Sec. 393.83  Exhaust systems.

    (a) Every motor vehicle having a device (other than as part of its 
cargo) capable of expelling harmful combustion fumes shall have a system 
to direct the discharge of such fumes. No part shall be located where 
its location would likely result in burning, charring, or damaging the 
electrical wiring, the fuel supply, or any combustible part of the motor 
vehicle.
    (b) No exhaust system shall discharge to the atmosphere at a 
location immediately below the fuel tank or the fuel tank filler pipe.
    (c) The exhaust system of a bus powered by a gasoline engine shall 
discharge to the atmosphere at or within 6 inches forward of the 
rearmost part of the bus.
    (d) The exhaust system of a bus using fuels other than gasoline 
shall discharge to the atmosphere either:
    (1) At or within 15 inches forward of the rearmost part of the 
vehicle; or
    (2) To the rear of all doors or windows designed to be open, except 
windows designed to be opened solely as emergency exits.
    (e) The exhaust system of every truck and truck tractor shall 
discharge to the atmosphere at a location to the rear of the cab or, if 
the exhaust projects above the cab, at a location near the rear of the 
cab.
    (f) No part of the exhaust system shall be temporarily repaired with 
wrap or patches.
    (g) No part of the exhaust system shall leak or discharge at a point 
forward of or directly below the driver/sleeper compartment. The exhaust 
outlet may discharge above the cab/sleeper roofline.
    (h) The exhaust system must be securely fastened to the vehicle.
    (i) Exhaust systems may use hangers which permit required movement 
due to expansion and contraction caused by heat of the exhaust and 
relative motion between engine and chassis of a vehicle.

[53 FR 49401, Dec. 7, 1988]