[Code of Federal Regulations]
[Title 49, Volume 4]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR325.91]

[Page 801]
 
                        TITLE 49--TRANSPORTATION
 
                      DEPARTMENT OF TRANSPORTATION
 
PART 325_COMPLIANCE WITH INTERSTATE MOTOR CARRIER NOISE EMISSION STANDARDS
--Table of Contents
 
                   Subpart G_Exhaust Systems and Tires
 
Sec. 325.91  Exhaust systems.


    A motor vehicle does not conform to the visual exhaust system 
inspection requirements, 40 CFR 202.22, of the Interstate Motor Carrier 
Noise Emission Standards, if inspection of the exhaust system of the 
motor vehicle discloses that the system--
    (a) Has a defect which adversely affects sound reduction, such as 
exhaust gas leaks or alteration or deterioration of muffler elements, 
(small traces of soot on flexible exhaust pipe sections shall not 
constitute a violation of this subpart);
    (b) Is not equipped with either a muffler or other noise dissipative 
device, such as a turbocharger (supercharger driven by exhaust gases); 
or
    (c) Is equipped with a cut-out, by-pass, or similar device, unless 
such device is designed as an exhaust gas driven cargo unloading system.