(a) Vehicles comprising a test sample which are required to be tested, pursuant to a test order issued in accordance with this subpart, will be selected at the location and in the manner specified in the test order. If a manufacturer determines that the test vehicles cannot be selected in the manner specified in the test order, an alternative selection procedure may be employed: Provided, That the manufacturer requests approval of the alternative procedure in advance of the start of test sample selection and that the Administrator approves the procedure. Special order vehicles are exempt from sample selection unless a test sample cannot be completed otherwise.

(b) The manufacturer shall have assembled the test vehicles of the configuration selected for testing using its normal mass production processes for vehicles to be distributed into commerce. During the audit, the manufacturer shall inform the Administrator of any change(s) implemented in its production processes, including quality control, which may be reasonably expected to affect the emissions of the vehicles selected, between the time the manufacturer received the test order and the time the manufacturer finished selecting test vehicles.

(c) No quality control, testing, or assembly procedures will be used on the completed test vehicles or any portion thereof, including parts and subassemblies, that has not been or will not be used during the production and assembly of all other vehicles of that configuration.

(d) The test order may specify that EPA Enforcement Officers, rather than the manufacturer, will select the test vehicles according to the method described in paragraph (a) of this section.

(e) The order in which test vehicles are selected determines the order in which test results are to be used in applying the sampling plan in accordance with § 86.610.

(f) The manufacturer shall keep on hand all untested vehicles, if any, comprising the test sample until a pass or fail decision is reached in accordance with paragraph (d) of § 86.610. The manufacturer may ship any tested vehicle which has not failed in accordance with paragraph (a) of § 86.610. However, once a manufacturer ships any vehicle from the test sample, it relinquishes the prerogative to conduct retests provided in paragraph (i) of § 86.608.