[Code of Federal Regulations]
[Title 40, Volume 17]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR86.004-40]

[Page 60-61]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 86_CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND 
ENGINES--Table of Contents
 
Subpart A_General Provisions for Emission Regulations for 1977 and Later 
 
Sec. 86.004-40  Heavy-duty engine rebuilding practices.

    The provisions of this section are applicable to heavy-duty engines 
subject to model year 2004 or later standards and are applicable to the 
process of engine rebuilding (or rebuilding a portion of an engine or 
engine system). The process of engine rebuilding generally includes 
disassembly, replacement of multiple parts due to wear, and reassembly, 
and also may include the removal of the engine from the vehicle and 
other acts associated with rebuilding an engine. Any deviation from the 
provisions contained in this section is a prohibited act under section 
203(a)(3) of the Clean Air Act (42 U.S.C. 7522(a)(3)).
    (a) When rebuilding an engine, portions of an engine, or an engine 
system, there must be a reasonable technical basis for knowing that the 
resultant engine is equivalent, from an emissions standpoint, to a 
certified configuration (i.e., tolerances, calibrations, specifications) 
and the model year(s) of the resulting engine configuration must be 
identified. A reasonable basis would exist if:
    (1) Parts installed, whether the parts are new, used, or rebuilt, 
are such that a person familiar with the design and function of motor 
vehicle engines would reasonably believe that the parts perform the same 
function with respect to emissions control as the original parts; and
    (2) Any parameter adjustment or design element change is made only:
    (i) In accordance with the original engine manufacturer's 
instructions; or
    (ii) Where data or other reasonable technical basis exists that such 
parameter adjustment or design element change, when performed on the 
engine or similar engines, is not expected to adversely affect in-use 
emissions.
    (b) When an engine is being rebuilt and remains installed or is 
reinstalled in the same vehicle, it must be rebuilt to a configuration 
of the same or later model year as the original engine. When an engine 
is being replaced, the

[[Page 61]]

replacement engine must be an engine of (or rebuilt to) a configuration 
of the same or later model year as the original engine.
    (c) At time of rebuild, emissions-related codes or signals from on-
board monitoring systems may not be erased or reset without diagnosing 
and responding appropriately to the diagnostic codes, regardless of 
whether the systems are installed to satisfy requirements in Sec. 
86.004-25 or for other reasons and regardless of form or interface. 
Diagnostic systems must be free of all such codes when the rebuilt 
engine is returned to service. Such signals may not be rendered 
inoperative during the rebuilding process.
    (d) When conducting a rebuild without removing the engine from the 
vehicle, or during the installation of a rebuilt engine, all critical 
emissions-related components listed in Sec. 86.004-25(b) not otherwise 
addressed by paragraphs (a) through (c) of this section must be checked 
and cleaned, adjusted, repaired, or replaced as necessary, following 
manufacturer recommended practices.
    (e) Records shall be kept by parties conducting activities included 
in paragraphs (a) through (d) of this section. The records shall include 
at minimum the mileage and/or hours at time of rebuild, a listing of 
work performed on the engine and emissions-related control components 
including a listing of parts and components used, engine parameter 
adjustments, emissions-related codes or signals responded to and reset, 
and work performed under paragraph (d) of this section.
    (1) Parties may keep records in whatever format or system they 
choose as long as the records are understandable to an EPA enforcement 
officer or can be otherwise provided to an EPA enforcement officer in an 
understandable format when requested.
    (2) Parties are not required to keep records of information that is 
not reasonably available through normal business practices including 
information on activities not conducted by themselves or information 
that they cannot reasonably access.
    (3) Parties may keep records of their rebuilding practices for an 
engine family rather than on each individual engine rebuilt in cases 
where those rebuild practices are followed routinely.
    (4) Records must be kept for a minimum of two years after the engine 
is rebuilt.

[62 FR 54729, Oct. 21, 1997, as amended at 66 FR 5160, Jan. 18, 2001]