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2002–2005 Honda Civic Si EM2 Cold Air Intake (K20A2 / K20A3)
This Flashark Cold Air Intake is engineered for the 2002–2005 Honda Civic Si EM2 (K20A2 / K20A3) and replaces the factory airbox and intake tube with a 3.0" mandrel-bent aluminum tube routed to an inner-fender cold-air feed. The sealed heat-shielded inlet keeps intake charge cooler than the stock airbox, while the included dry, reusable filter preserves factory MAF calibration without a tune. A typical home installer can finish the bolt-on swap in about 90 minutes with basic hand tools.
Specifications
| Spec | Detail |
|---|---|
| Brand | Flashark |
| System Type | Cold Air Intake (CAI) |
| Material | 6061-T6 aluminum (intake tube) |
| Tube Diameter | 76mm (3.0") |
| Filter Type | Dry, washable, reusable (no oil required) |
| Filter Size | 4.5" conical with velocity stack |
| MAF Housing | CNC-machined 76mm, factory MAF location retained |
| Intake Temp Reduction | Approximately 15–25°F vs. stock (factory airbox baseline) |
| Tune Required | No — plug-and-play with factory K20 ECU |
| Install Time | Approximately 90 minutes (hand tools) |
| Warranty | 1 Year |
Key Features
- 3.0" mandrel-bent 6061-T6 aluminum tube: Smooth interior with no step-downs, matched to the K20A2 / K20A3 throttle body bore for steady airflow through the EM2 engine bay.
- 4.5" conical dry filter with integrated velocity stack: Washable, reusable, no oil required — won't foul the MAF sensor and keeps filter maintenance simple across high-RPM driving.
- Inner-fender cold-air routing: Heat shield behind the inner liner pulls ambient air from outside the bay instead of engine-bay heat, so intake charge runs cooler than the stock airbox.
- CNC-machined 76mm MAF housing: Designed to retain the factory MAF sensor location and bore so the K20A2 (2004–2005) and K20A3 (2002–2003) ECU calibration stays within the OEM envelope.
- No tune required: Works with the stock K20 ECU and remains compatible with Hondata / K-Pro if the car is already tuned.
- Bolt-on installation: OEM-spec mounting points; about 90 minutes with basic hand tools.
Who this kit is for
This Flashark Cold Air Intake fits the 2002–2005 Honda Civic Si EM2 with the 2.0L K20A2 / K20A3 engine.
✓ For you if… you drive an EM2 Civic Si and want a sealed cold-air box that pulls from outside the bay · you prefer a washable dry filter over disposable paper elements · you want a first bolt-on K-series upgrade that doesn't require a tune · you want a 90-minute install with hand tools · you've confirmed your county / state emissions rules in the Compliance section below.
✗ Not for you if… your Civic is a 2001 D17, a 2001–2005 LX / EX / DX / HX, or a 2006–2011 EP3 / FG2 / 2012–2015 FB6 Si (different chassis and engine) · you've done a K-swap into an EG / EK / DC2 / EP3 and need a swap adapter (not included) · you need an OEM-replacement airbox or factory paper element · you're in a CARB-adopting state and this SKU carries no EO (see Compliance section) · you regularly ford deep water without a filter relocation (see hydrolock note in Check Before Ordering).
Check before ordering
- Vehicle match: Exact-fit for the 2002–2005 Honda Civic Si EM2 with the 2.0L K20A2 (2004–2005) or K20A3 (2002–2003). Does NOT fit: the 2001 Civic D17, any 2001–2005 Civic LX / EX / DX / HX (different engine and chassis), the 2006–2011 Civic Si EP3 / FG2, or the 2012–2015 Civic Si FB6 (K24Z7). K-swap installs into EG / EK / DC2 / EP3 require a swap adapter that is not included — message us before ordering.
- Intake type: Sealed heat-shielded box with an inner-fender inlet — a true cold-air intake, not a short-ram.
- Filter care: Dry filter, no oil required; clean and reuse per the kit instructions. No re-oiling step, so there's no risk of over-oiling the MAF.
- Sensors & throttle body: Designed to retain the factory MAF sensor location and 76mm bore, matched to the stock K20 throttle body. No spacer or adapter is required for the listed applications.
- Legality: This SKU does not carry a CARB Executive Order. See the Compliance section below for the state-by-state rule before you order.
- Install & water exposure: Bolt-on with OEM-spec mounting points, about 90 minutes, basic hand tools. The filter sits low in the inner-fender area — avoid deep water crossings; water ingestion can cause hydrolock and severe engine damage.
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What's in the box
- 1× 76mm (3.0") mandrel-bent 6061-T6 aluminum intake tube
- 1× 4.5" dry conical air filter with velocity stack (washable and reusable)
- 1× Inner-fender heat shield / airbox
- 1× CNC-machined 76mm MAF sensor housing
- 1× Multi-layer silicone coupler with stainless T-bolt clamps
- 1× Installation hardware kit
Shipping & Returns
Free U.S. Shipping: Orders are typically processed within 1–2 business days and delivered within 7–9 business days. Additional charges may apply to remote areas.
30-Day Returns: Unopened and unused items in their original packaging may be returned within 30 days of receipt. Return shipping is covered for verified quality issues.
Worry-Free Delivery: Optional protection against eligible loss, theft, delay, or transit damage is available at checkout.
| Year | Make | Model | Engine |
|---|---|---|---|
| 2002 | Honda | Civic Si (EM2) | 2.0L I4 (K20A3) |
| 2003 | Honda | Civic Si (EM2) | 2.0L I4 (K20A3) |
| 2004 | Honda | Civic Si (EM2) | 2.0L I4 (K20A2) |
| 2005 | Honda | Civic Si (EM2) | 2.0L I4 (K20A2) |
Note: Does NOT fit 2001 Civic (D17), 2006–2011 Civic Si EP3/FG2 (different chassis), 2012–2015 Civic Si FB6 (K24Z7), or any Civic 1.7L/1.8L non-Si variant. K-swap compatibility (EG/EK/DC2/EP3) requires an adapter — not included.
2002–2005 Honda Civic Si EM2 Cold Air Intake FAQs
Q1: Is this cold air intake legal in my state?
A1: This kit does not carry a CARB Executive Order. Not legal for sale or use in California (and other CARB-adopting states). For closed-course competition or off-road use where state law permits, the kit can be installed without auction.
Q2: Will this fit my Honda Civic?
A2: This kit is engineered for the 2002–2005 Honda Civic Si EM2 with the 2.0L K20A2 (2004–2005) or K20A3 (2002–2003). It does NOT fit the 2001 Civic D17, any 2001–2005 Civic LX / EX / DX / HX, the 2006–2011 Civic Si EP3 / FG2, the 2012–2015 Civic Si FB6 (K24Z7), or any non-Si 1.7L / 1.8L Civic. K-swap installations into EG / EK / DC2 / EP3 require a swap adapter that is not included — message us with your VIN before ordering if your Civic is outside the EM2 Si list above.
Q3: How much horsepower will this add?
A3: Typical intake-only gains for a naturally aspirated K20A2 / K20A3 application are approximately +3–10 hp and +3–10 lb-ft of torque. Actual results depend on the vehicle's condition, calibration, the quality of the install, and any supporting hardware. The factory ECU stays within its OEM MAF envelope, so this kit is meant as a throttle-response and intake-tone upgrade rather than a peak-power upgrade.
Q4: Will a cold air intake improve my MPG?
A4: MPG is dominated by driving habits; an intake alone can't guarantee a measurable gain. Expect the main benefits as sharper throttle feel and a deeper intake tone under acceleration rather than fuel economy. An intake alone can't guarantee a measurable gain.
Q5: Will this void my warranty?
A5: Under the Magnuson-Moss Warranty Act, an aftermarket part cannot void your factory warranty unless the manufacturer proves it caused the failure. This kit is a direct bolt-on replacement that keeps the factory MAF sensor location and connectors, so it does not require any factory wiring changes.
Q6: Will it throw a check engine light (CEL)?
A6: This kit is designed to retain the factory MAF / IAT sensor location and 76mm bore, which keeps the MAF calibration within the OEM design envelope. A CEL is usually the result of an intake leak, an over-oiled filter (not applicable with this dry filter), or a mismatched sensor bore — none of which apply when this kit is installed as designed.
Q7: Do I need a tune after installing?
A7: No tune is required. The factory 76mm MAF housing is retained and the stock K20 ECU calibration stays within the OEM envelope, so the kit is plug-and-play. If you've already installed Hondata / K-Pro, the kit is designed to remain compatible with that calibration.
Q8: Is this safe in rain or deep water?
A8: Normal rain driving is fine — the filter is fed through the inner-fender cold-air routing. Avoid deep water crossings; water ingestion can cause hydrolock and severe engine damage. Consider a high-mounted intake or filter relocation if you regularly ford water.
Q9: How do I clean and re-oil the filter?
A9: This kit ships with a dry, washable filter that requires no oil. Clean per the kit instructions using a mild filter cleaner, let it air-dry fully, and reinstall. There is no re-oiling step, so there is no risk of over-oiling the MAF sensor.
Q10: What does it sound like?
A10: You'll hear a deeper intake tone under acceleration; at cruise it quiets down. Sound is subjective — this is a sealed cold-air box, so it stays quieter than an open-element short-ram setup. If you want the loudest option, look at a short-ram intake instead.
Q11: What's included / what do I still need?
A11: The box includes the 76mm mandrel-bent aluminum intake tube, the 4.5" dry conical filter, the inner-fender heat shield / airbox, the CNC-machined 76mm MAF sensor housing, the multi-layer silicone coupler with stainless T-bolt clamps, and the installation hardware kit. The factory MAF / IAT sensors are reused (not included). You supply basic hand tools — no cutting or ECU tuning is required.
Q12: Will it work with my aftermarket throttle body or K-swap setup?
A12: This kit is engineered for the factory 76mm K20A2 / K20A3 throttle body bore. If you have installed an oversized aftermarket throttle body, verify the coupler size with our support team before ordering. K-swap installations into EG / EK / DC2 / EP3 chassis require a swap adapter that is not included — message us with your build details before ordering.
Fast Shipping Policy
Your order will be dispatched within 1-2 business days, and the package will arrive within your order's estimated date. Click for Shipping Policy
Easy Return Policy
Every order comes with a 30-day free return, provided the item is brand new, uninstalled, and in its original packaging. We cover return shipping for quality issues. Refunds are processed within 3-5 business days. Click for Return Policy
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