40 CFR §1045.335

1. (a)Send us a written report asking us to reinstate your suspended certificate. In your report, identify the reason for noncompliance, propose a remedy for the engine family, and commit to a date for carrying it out. In your proposed remedy include any quality control measures you propose to keep the problem from happening again.
2. (b)Give us data from production-line testing that shows the remedied engine family complies with all the emission standards that apply.