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Intake replacement air filter
aFe 21-91151 uses Pro DRY S oil-free synthetic media. Match the exact aftermarket intake, sealing interface and dimensions below before ordering.
Key Features
- Three layers of oil-free synthetic media. Washable and reusable; no oil is required during maintenance.
- Polyurethane top and base with the flange and top shape specified below.
- Oil-free media: do not apply filter oil. Match the exact Pro DRY S service instructions.
Fitment
| Application | Required checks |
|---|---|
| Specification-matched aFe intake replacement | Manufacturer expressly lists replacement for aFe Momentum intakes 50-70046R and 50-70046D. External locking tabs provide the filter-to-housing interface; match the exact intake and flange. Molded-in expanded metal provides impact protection. |
Replacing a filter in an aftermarket intake does not establish a factory-airbox or vehicle-wide fitment claim.
Specifications
| Brand | aFe POWER |
|---|---|
| Manufacturer Part Number | 21-91151 |
| Media | Pro DRY S: three layers of oil-free synthetic media |
| Flange internal diameter | 2-1/2 in |
| Base | 4-1/2 in |
| Top | 4-1/2 in, inverted |
| Height | 7 in |
| Construction | Polyurethane top and base |
| Service | Washable and reusable; correct aFe synthetic-media cleaner, no filter oil |
| Emissions statement | Manufacturer states that this filter does not require a CARB EO number. Complete intake compliance must be checked separately. |
What's Included
One Pro DRY S air filter and the stainless steel clamp expressly listed by the manufacturer.
The generic manufacturer specifications also say “Coupler Included: Yes,” but no separate coupling is identified in the detailed contents. A coupling is not independently confirmed supplied.
About aFe Power
aFe Power develops application-specific intake, filtration, exhaust, cooling, tuning, suspension, drivetrain, and truck-performance components supported by product testing and documented installation requirements.
Related Parts
- Exact manufacturer filter specifications
- Manufacturer filter maintenance guidance
- Shop the complete aFe Power collection
Frequently Asked Questions
Which intake does this filter fit?Manufacturer expressly lists replacement for aFe Momentum intakes 50-70046R and 50-70046D. External locking tabs provide the filter-to-housing interface; match the exact intake and flange. Molded-in expanded metal provides impact protection.
Does Pro DRY S require oil?No. This exact filter uses three layers of oil-free synthetic media. Do not apply filter oil or use the oiling procedure for a cotton-gauze Pro 5R filter.
What dimensions should I check?Flange 2-1/2 in; base 4-1/2 in; top 4-1/2 in, inverted; height 7 in. Match the full sealing interface and surrounding clearance.
What comes with the filter?One Pro DRY S air filter and the stainless steel clamp expressly listed by the manufacturer. A generic coupler-included field is not an itemized coupling confirmation.
How should I service the oil-free media?Use the current manufacturer cleaning instructions for Pro DRY S and the specified aFe cleaner. Allow the filter to dry completely before reuse. Do not oil the synthetic media or substitute an oiled-filter recharging procedure.
How often should it be serviced?Inspect according to dust exposure, filter condition and restriction. Follow the current instructions for the installed synthetic-media filter. Dusty conditions can require earlier service; no fixed interval is certified by this listing.
Does it replace a factory panel filter?This listing is for an intake replacement element. Do not assume factory-airbox drop-in compatibility or reuse unrelated factory-panel installation steps.
Is a CARB EO required for the filter?The manufacturer states this filter does not require a CARB EO number. That does not certify an entire aftermarket intake or establish its vehicle-specific emissions approval.
Installation Instructions
Confirm aFe 21-91151 and the exact intake assembly. Keep debris out of the clean intake, inspect the housing seal and seat the filter using the specified locking or retention interface. Follow the applicable intake manual for access, orientation and any supplied clamp. No numeric clamp torque is established by the current filter page.
Important Disclosures
California Proposition 65 warning: this product can expose you to chemicals known to the State of California to cause cancer and reproductive harm.
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