40 CFR §1068.445

1. (a)We may revoke your certificate for a family in the following cases:
   1. (1)You do not meet the reporting requirements under this subpart.
   2. (2)Your family fails an SEA and your proposed remedy to address a suspended certificate is inadequate to solve the problem or requires you to change the engine/equipment's design or emission control system.
2. (b)To sell engines/equipment from a family with a revoked certificate of conformity, you must modify the family and then show it complies with the applicable requirements.
   1. (1)If we determine your proposed design change may not control emissions for the engine/equipment's full useful life, we will tell you within five working days after receiving your report. In this case we will decide whether production-line testing will be enough for us to evaluate the change or whether you need to do more testing.
   2. (2)Unless we require more testing, you may show compliance by testing production-line engines/equipment as described in this subpart.
   3. (3)We will issue a new or updated certificate of conformity when you have met these requirements.