Section 86.1901 - What testing requirements apply to my engines that have gone into service?(a) If you manufacture diesel heavy-duty engines above 8,500 lbs. GVWR that are subject to engine-based exhaust emission standards under this part, you must test them as described in this subpart. You must measure all emissions listed in § 86.1910(d) other than PM beginning in calendar year 2005 and you must measure PM emissions beginning in calendar year 2007. See§ 86.1930 for special provisions that may apply to manufacturers in the early years of this program.(b) We may void your certificate of conformity for an engine family if you do not meet your obligations under this subpart. We may also void individual tests and require you to retest those vehicles or take other appropriate measures in instances where you have not performed the testing in accordance with the requirements described in this subpart.(c) In this subpart, the term "you" refers to the certificate-holder for any engines subject to the requirements of this subpart.(d) In this subpart, round means to round numbers according to NIST Special Publication 811(incorporated by reference in § 86.1 ). 70 FR 34619 , June 14, 2005, as amended at 75 FR 68459 , Nov. 8, 2010