AEM 21-798C Cold Air Intake System (Non-Carb Compliant)

✔ Vehicle Fitment

• Honda Civic 1.5T (non-Si) — model years 2016 thru 2021.

• Works across trims that share the 1.5T engine (sedan & hatch).

• Does not fit the Civic Si or Type R (different intake/engine).

The AEM 21-798C Performance Cold Air Intake System produces horsepower and torque gains by replacing your vehicle’s restrictive factory air filter and air intake housing. This air intake system was designed, tuned and dyno-tested to fit specific Honda Civic models.

Why Upgrade with the 21-798C?

• The OEM intake is relatively restrictive for a turbo application; this upgrade opens up airflow and reduces intake-path bottlenecks.

• Sharper throttle response — because more air = better reaction.

• Improved induction sound — you’ll actually hear the turbo motor breathe.

• AEM Dryflow oil-free washable filter: high-flow, long service interval (up to 100,000 miles in ideal condiitons).

• Mandrel-bent aluminum intake tubing with gun-metal grey powder coat — looks good under the hood.

• Engineered for direct fitment and compatibility with factory emissions/MAF sensor setup.

Air enters the system through an oversized AEM Dryflow synthetic washable air filter for outstanding air flow, filtration and performance. The air filter is placed under the original air box space and above the driver-side wheel well which is designed to pull in cooler outside air and increase horsepower.

Key Features

• Mandrel-bent aluminum intake tube, gun-metal finish.

• High-flow AEM Dryflow synthetic filter (oil-free, washable).

• Filter positioned in factory-air-box location above driver-side wheel well for cooler intake air.

• Tune and dyno-tested for the specified Civic 1.5T platforms.

• Backed by AEM’s lifetime limited warranty.

• Legal note: Some versions are not legal for sale or use in California or states with similar emission rules.

The air intake tube is constructed from mandrel-bent aluminum featuring a durable gunmetal gray powder coated finish. This air intake system was developed to accommodate the engine’s factory emissions control devices including the mass air flow sensor.

Performance Expectations

• Quicker throttle tip-in and more immediate reaction from the engine.

• Better mid- to high-RPM airflow for the turbo motor, which helps especially when pushing hard or upgrading other parts later.

• More engaging driver experience — you’ll feel the difference even if the dyno numbers aren’t massive.

• Real-world gains reported around +10 HP in some user threads.

• Provides strong foundation for further upgrades (exhaust, tuning, turbo bolt-ons) if you choose that route.

The tapered cylinder shaped AEM Dryflow air filter is made from an oil-free, synthetic filter media that can be used for up to 100,000 miles before cleaning is needed (depending on driving conditions).

Daily-Driver Friendly

Yes — this intake keeps things practical:

• Works fine with stock ECU and tune; no must-have immediate flash required to benefit.

• Filter is low-maintenance (oil-free) and durable.

• Keeps your Civic reliable and street-friendly, just more fun.

• Just double-check your compliance if you live in a state with stricter emissions rules.

The air intake system is backed by AEM’s Lifetime Limited Warranty. Some AEM air intakes are not legal for sale or use in California and other states adopting California emission standards, while others are 50 state legal. View the AEM 21-798C vehicle applications to determine the legal status for each vehicle.