Section 204.57-4 - Testing(a) The manufacturer shall conduct one valid test in accordance with the test procedures specified in § 204.54 for each compressor selected for testing pursuant to this subpart.(b) No maintenance will be performed on test compressors, except as provided for by § 204.57-3 . In the event a compressor is unable to complete the emission test, the manufacturer may replace the compressor. Any replacement compressor will be a production compressor of the same configuration, and the replacement compressor will be randomly selected from the batch sample and will be subject to all the provisions of these regulations.