40 CFR 63.2991 - When must I conduct performance tests?
(a)Initially. You must conduct an initial performance test no later than 180 days after the applicable compliance date specified in § 63.2985. The initial performance test is used to demonstrate initial compliance and establish operating parameter limits and ranges to be used to demonstrate continuous compliance with the emission standards.
(c)To change your OMM plan. You must conduct a performance test according to the requirements specified in § 63.2992 to change the limit or range for any operating limit specified in your OMM plan established during a previous compliance test.