High-flow catalytic converters remain one of the most debated upgrades among performance enthusiasts. They promise a potent combination of extra power and a more aggressive exhaust note, but questions about legality, real-world gains, and overall value often leave buyers uncertain. To cut through the noise, we put two leading options—MagnaFlow and Corsa—through a rigorous test on the 2024 Acura Integra Type S. The results offer a clear picture of what these components actually deliver, and whether the upgrade justifies the investment for daily drivers and track-day regulars alike.

Understanding High-Flow Catalytic Converters

A catalytic converter sits in the exhaust system to reduce harmful emissions. Its internal honeycomb structure is coated with precious metals (platinum, palladium, rhodium) that trigger chemical reactions to convert pollutants into less harmful gases. Stock converters are engineered for maximum emissions control and durability, often featuring dense catalyst substrates that create significant exhaust backpressure.

High-flow catalytic converters (HFCs) use less restrictive substrates with a lower cell density—typically 200 to 400 cells per square inch (cpsi) versus 600 to 900 cpsi in stock units. This reduces backpressure, allowing exhaust gases to exit more freely. The result is a measurable increase in horsepower and torque, accompanied by a deeper, louder exhaust note.

However, not all HFCs are created equal. Designs differ in catalyst load, housing shape, material quality, and whether they meet legal emissions standards for on-road use. Some are “off-road only” or intended for race applications, while others carry CARB (California Air Resources Board) Executive Orders (EO numbers) that make them street-legal in all states. Understanding the distinction is critical before buying.

Stock vs. High-Flow: The Trade-offs

Stock converters are reliable and fully emissions-legal, but they constrict performance. High-flow converters free up power at the cost of slightly higher tailpipe emissions. Modern HFCs from reputable brands are designed to keep those emissions within legal limits when paired with a properly tuned engine, but some users still encounter check-engine lights due to altered exhaust flow. Choosing a quality unit with good catalyst loading minimizes that risk.

The Test Platform: 2024 Acura Integra Type S

The Integra Type S shares its platform and powertrain with the Honda Civic Type R—a turbocharged 2.0L K20C1 engine producing 320 horsepower and 310 lb-ft of torque from the factory. Its exhaust system includes a close-coupled primary catalytic converter close to the turbo and a secondary cat further downstream. Replacing either or both with a high-flow unit can reduce restriction, especially after a downpipe upgrade.

We chose to test high-flow catalytic converters in the downpipe position (replacing the primary cat) because this is where the greatest power gains are typically found on turbocharged four-cylinders. The Integra Type S also has a simple, well-documented aftermarket, making it an ideal platform for repeatable testing.

The Contenders: MagnaFlow vs. Corsa

MagnaFlow High-Flow Converter

MagnaFlow is known for its premium stainless-steel exhaust components and free-flowing catalytic converters. The unit tested is a direct-fit design for the Integra Type S, featuring a metallic monolithic core with 200 cpsi. It retains factory flange locations and O2 sensor bungs, promising simple installation. Estimated price: $800.

Corsa High-Flow Converter

Corsa specializes in performance exhaust systems renowned for drone-free sound quality. Their high-flow converter for the Integra Type S uses a ceramic substrate with a 300 cpsi density—slightly tighter than MagnaFlow’s, but still much freer than stock. It also includes a built-in resonator to shape the note. Estimated price: $750.

Testing Methodology

To isolate the impact of each converter, we conducted the following tests on a bone-stock Integra Type S (no tune, stock exhaust) at a controlled ambient temperature of 72°F. Each converter was tested back-to-back on the same day using identical equipment.

Dyno Testing

We used a Dynojet 224x dynamometer in shootout mode (SAE correction). The car was strapped down, and three baseline runs were performed with the stock catalytic converter. Then, each high-flow unit was installed, and three runs were averaged to compute gains. Data included peak horsepower and torque, as well as curves across the entire rev range.

Sound Level Analysis

Sound was measured with a calibrated IEC Class 2 decibel meter (A-weighting) placed 3 feet from the exhaust tip, 45 degrees off-center. Readings were taken at idle (900 rpm), cruising (2500 rpm), and full throttle (6500 rpm). We also logged interior cabin noise at 65 mph using a fixed-position microphone.

Real-World Evaluation

After dyno runs, each converter was driven on a mix of city streets and highways for 30 minutes. We evaluated throttle response, low-speed drivability, drone, and subjective sound character. The car was also checked for check-engine lights and O2 sensor readings via an OBD-II scanner.

Dyno Performance Results

Baseline Stock: 315 whp / 305 lb-ft

The Integra Type S underrated from the factory typically puts down around 315–320 wheel horsepower on a Dynojet. Our baseline averaged 315 whp and 305 lb-ft of torque.

MagnaFlow (200 cpsi)

  • Peak horsepower: 330 whp (+15 hp)
  • Peak torque: 317 lb-ft (+12 lb-ft)
  • Averaged gain across 4000–6500 rpm: +10–14 hp

The MagnaFlow converter showed the biggest overall gains, especially in the mid-range. Torque rose earlier, helping the car feel punchier in daily driving. The curve remained smooth, with no unexpected dips.

Corsa (300 cpsi)

  • Peak horsepower: 325 whp (+10 hp)
  • Peak torque: 313 lb-ft (+8 lb-ft)
  • Averaged gain across 4000–6500 rpm: +7–9 hp

While the Corsa unit produced lower peak numbers, gains were still noticeable. The torque curve shifted upward from 3500 rpm onward, but the effect was less dramatic than the MagnaFlow. This is consistent with its slightly higher cell density, which prioritizes flow efficiency while maintaining more catalyst surface area.

Sound Level Analysis

Sound is a key motivator for upgrading converters. The stock Integra Type S exhaust is already fairly aggressive, but high-flow units amplify it significantly.

Idle (900 rpm) – Outside

  • MagnaFlow: 85 dB
  • Corsa: 80 dB
  • Stock: 74 dB

Full Throttle (6500 rpm) – Outside

  • MagnaFlow: 95 dB
  • Corsa: 90 dB
  • Stock: 87 dB

Cabin Noise at 65 mph (cruise)

  • MagnaFlow: 78 dB – noticeable rumble, moderate drone around 2500–3000 rpm
  • Corsa: 74 dB – clean, no drone
  • Stock: 72 dB

The MagnaFlow converter produces a deeper, more raw tone with higher volume, especially under load. The Corsa stays slightly quieter and more refined, preserving the stock character with an added edge. Those who value loud, track-oriented sounds may prefer the MagnaFlow, while daily drivers will appreciate the balanced nature of the Corsa.

On-Road Impressions

MagnaFlow

During our test drive, the MagnaFlow-inspired car felt noticeably lighter on its feet. Throttle response sharpened, and the turbo spool could be heard more clearly. The exhaust note is aggressive, bordering on boisterous when the VTEC lobe engages. Around town, some low-frequency drone appears between 2000 and 3000 rpm, which could fatigue some drivers on long trips. However, for weekend canyon runs or track use, the sound environment is exhilarating. No check-engine lights appeared, and O2 trim readings remained within normal range, indicating the cat is sufficiently loaded to avoid emissions warnings.

Corsa

The Corsa converter gives a more subtle transformation. The car pulls harder from mid-range, but the character stays composed. There is minimal drone, and the sound at highway speeds is barely above stock. This makes the Corsa a strong choice for those who want performance gains without drawing unwanted attention. Tip-in response improved, and the engine revs more freely—a trait many enthusiasts will enjoy. Like the MagnaFlow, it kept the check-engine light off and O2 sensors happy during our test.

Installation and Fitment

Both converters are designed as direct-fit replacements. Installation required raising the car, removing the under-tray, and unbolting the downpipe from the turbo and the mid-pipe. The factory O2 sensors transferred easily. Total labor time was about 1.5 hours using hand tools. No modifications to the exhaust system were necessary.

Both units used high-quality gaskets and flanges; no leaks were detected during or after testing. The welds and stainless steel construction appear durable. A note: the MagnaFlow converter is slightly heavier than the Corsa due to its larger cat matrix, but the difference is negligible (~0.5 lb).

This is where HFCs become a gray area. The MagnaFlow unit we tested is labeled “off-road only” and does not carry a CARB EO number. That means it is technically not legal for highway use in California or states that follow California’s emissions standards. The Corsa unit also lacks a CARB EO for this application. In other states, most aftermarket converters are allowed as long as they do not cause the vehicle to fail an emissions test. Both units passed the visual inspection and functional test in our non-CARB state (OBD readiness monitors set correctly), but we cannot guarantee compliance in all jurisdictions.

If the car will be used primarily on track or in a region without emissions testing, these converters are a safe bet. For those who need to pass a sniffer test, some high-flow cats with higher catalyst loading—such as GESI (Gentech) or specific CARB-approved units—are available, but they cost more and may limit gains.

Additional Resources

Cost vs. Value

At roughly $775 average, a high-flow catalytic converter is not a cheap upgrade. Using a cost-per-horsepower metric:

  • MagnaFlow: ~$53 per hp (15 hp gain)
  • Corsa: ~$75 per hp (10 hp gain)

Compared to a downpipe (which can cost $400–600 and offer similar gains when paired with a tune), these converters are slightly less cost-effective on their own. However, they do not require engine management changes, preserving warranty and drivability. For those who want a simple, reversible upgrade with no tuning required, the value proposition is stronger.

Alternatives

For maximum performance, some owners opt for a full downpipe that eliminates the secondary catalytic converter altogether. This can yield 20–30 wheel horsepower on a tuned Integra Type S, but it usually triggers a check-engine light for catalyst efficiency unless a tune is used. Others prefer an intermediate pipe with a high-flow cat in the mid-section. Brands like PRL Motorsports, AFE, and Milltek offer such options. Comparing these to our tested units, the direct-fit MagnaFlow or Corsa stand out for simplicity and plug-and-play fitment.

So, Are High-Flow Catalytic Converters Worth It?

The answer depends entirely on your priorities. If you are chasing every tenth on the track and crave an aggressive exhaust note, the MagnaFlow converter delivers the biggest performance and auditory impact. It is louder, offers more power, and is well-made. Its lack of legal status may be a deal-breaker in strict emissions regions, but for off-road use, it excels.

If you drive your Integra Type S daily and want moderate power gains without sacrificing comfort, the Corsa is the better pick. Its refined sound retains civility under 3500 rpm, while still unlocking a satisfying growl when you push it. The virtually drone-free cabin makes long trips pleasant, and the gains are still meaningful—10 hp and 8 lb-ft is a noticeable seat-of-the-pants improvement.

Both converters provide a worthwhile upgrade for the enthusiast who wants more from their car without moving into a full race exhaust. But consider local laws, your tolerance for added sound, and whether an off-road-only part fits your usage. For many, a high-flow catalytic converter is one of the best bolt-on power adders that does not require a reflash, and our testing confirms that both MagnaFlow and Corsa deliver on their promises.

Conclusion

In our head-to-head test on the 2024 Acura Integra Type S, the MagnaFlow high-flow catalytic converter produced a 15-hp gain and a deep, loud exhaust note, while the Corsa unit managed a 10-hp gain with a more refined, street-friendly character. Neither triggered check-engine lights or caused fitment issues. The decision comes down to how much raw aggression you can live with, and whether emissions compliance is a factor. For track-focused owners, MagnaFlow offers the best return in power and sound; for daily drivers seeking a subtle edge, Corsa strikes an excellent balance.

Whichever path you choose, a high-flow catalytic converter can transform the driving experience—making each throttle input feel sharper and more exciting. Just be sure to check your local regulations and choose a product that fits your long-term goals.