EPA’s July 1 announcement uses the broad phrase “greenlight to certify” for its recognition of the SEMA Certified-Emissions program. The underlying agency letter is more precise.
EPA says the SC-E program, as SEMA described it, meets the emissions-testing criteria in the agency’s existing Tampering Policy. An aftermarket manufacturer or vendor may ordinarily rely on an SC-E certificate as reasonable documentation that a covered part does not adversely affect emissions.
That is a new recognized documentation route. It is not a repeal of the Clean Air Act’s tampering and defeat-device prohibitions, a blanket approval for aftermarket parts, or a promise that EPA will reach the same conclusion in every case.
The action applies an existing policy
The EPA response letter points back to the agency’s November 2020 Tampering Policy. That policy describes circumstances in which EPA typically exercises civil-enforcement discretion when a person has a documented, reasonable basis to conclude that conduct will not adversely affect emissions.
SEMA asked EPA in April 2026 to evaluate its SC-E program against those criteria. EPA’s July response says the program materials describe emissions testing that satisfies the policy’s requirements.
The letter does not create a new section of the Clean Air Act or a new regulation. It recognizes how one testing program can supply documentation under an existing, nonbinding enforcement policy.
How it developed
How the recognized documentation pathway developed
Tampering Policy issued
EPA described documented reasonable-basis pathways for conduct that does not adversely affect emissions while retaining enforcement discretion.
Program submitted for EPA evaluation
EPA’s response identifies an April 22 request to evaluate the SC-E program against the Tampering Policy.
SC-E testing recognized
EPA said the program materials, as described, satisfy the policy criteria and that certificates may ordinarily support reasonable documentation.
Exact application and facts still control
The policy remains nonbinding, documentation must match the represented application, and EPA retains case-by-case discretion.
What an SC-E certificate can establish
The core test is not whether a part is marketed as a repair or performance upgrade. It is whether the emissions evidence supports the exact altered application.
EPA’s Tampering Policy describes an emissions-testing pathway built around an appropriate vehicle, engine, or equipment item that has been identically altered. The test must show compliance with all applicable emissions requirements for the full useful life, and a marketed part must be limited to applications appropriately represented by the test product.
The July letter says SC-E testing, as described to EPA, follows that framework. It then states that manufacturers and vendors may ordinarily rely on an SC-E certificate as reasonable documentation that a part does not adversely affect emissions.
The certificate’s meaning is therefore application-specific. It cannot automatically be transferred to an unlisted model, engine, calibration, customized part, or materially different installation.
“Reasonable documentation” is not blanket immunity
The EPA announcement describes SEMA as an alternative certification authority and says the program can be used to show federal compliance.
The letter preserves a narrower legal and enforcement boundary. Its footnote says EPA retains discretion to vary from the Tampering Policy, considers each case independently, and evaluates all relevant facts and circumstances.
The 2020 policy says the same thing at greater length. It is nonbinding, is not final agency action, creates no obligation on a regulated party, and does not limit EPA’s authority to investigate or enforce the Clean Air Act.
For that reason, “recognized documentation pathway” is more exact than “every certified part is automatically legal.” The certificate can support the reasonable-basis record; it does not erase the statute or all fact-specific review.
The anti-tampering rules remain
The federal policy identifies two distinct prohibitions.
One covers tampering with emissions controls, including engine controls such as fueling and exhaust-gas recirculation and exhaust controls such as filters and catalysts. The other covers hardware or software whose principal effect is to bypass, defeat, or render an emissions-related device or design element inoperative.
EPA says those prohibitions apply throughout the life of a vehicle or engine, even after its regulatory useful life or warranty period ends.
The SC-E recognition does not create a general permission to remove a catalyst or filter, disable an emissions monitor, install a delete tune, or market a part outside the tested applications. Those questions remain governed by the Clean Air Act, the exact evidence, and the facts of the installation or sale.
Onboard diagnostics carry an additional boundary
The Tampering Policy says its usual reasonable-basis enforcement statement does not apply to conduct affecting an onboard diagnostic system. EPA may pursue that conduct regardless of its effect on emissions.
Nothing in the July letter creates a new OBD exception. A part’s emissions certificate therefore cannot be read as independent permission to falsify, disable, or render inaccurate required monitoring.
Federal recognition does not settle every state rule
EPA’s policy addresses federal Clean Air Act civil enforcement. It expressly says state and local law may separately regulate tampering, vehicle sales, registration, and inspection, and that the federal policy does not alter those obligations.
That boundary matters to the phrase “Freedom to Fix.” The July action changes the federal documentation landscape described by EPA. It does not make one certificate a universal answer across every jurisdiction and every vehicle application.
Scope and limits
The pathway and its retained boundaries
| Area | Recognized pathway | Still retained |
|---|---|---|
| SC-E certificate | Manufacturers and vendors may ordinarily rely on it as reasonable documentation that a covered part does not adversely affect emissions. | It is not a statutory exemption, and EPA may evaluate the facts of an individual case differently. |
| Emissions testing | An appropriately altered test vehicle must demonstrate compliance with the applicable emissions requirements. | The evidence does not automatically extend to unrepresented vehicles, engines, configurations, or customized versions of the part. |
| Tampering and defeat devices | A documented no-adverse-emissions basis may influence EPA’s civil enforcement discretion. | The Clean Air Act still prohibits qualifying acts that remove, bypass, defeat, or render emissions controls inoperative. |
| Onboard diagnostics | No new OBD exception is created by the SC-E recognition. | EPA’s policy says conduct affecting an OBD system may face enforcement regardless of its emissions effect. |
| Jurisdiction | The recognition addresses EPA’s federal Tampering Policy. | State and local anti-tampering, sales, registration, and inspection requirements remain separate. |
The narrow takeaway
EPA has recognized the SC-E program as a source of emissions-testing documentation under its existing Tampering Policy. That can give aftermarket businesses another way to document that an exact covered part does not adversely affect emissions.
The retained limits are equally important: application-specific evidence, the anti-tampering and defeat-device prohibitions, OBD restrictions, state and local rules, and EPA’s case-by-case discretion all remain.
This article describes the EPA records and is not legal advice or a determination that any particular part, vehicle, sale, or installation complies with applicable law.