You love your 2020 Honda Civic Si. It’s quick, it handles like a dream, and it’s a blast to drive. But let’s be honest: that factory exhaust sound? It leaves a little to be desired.
Maybe you’re chasing a few extra horsepower, a more aggressive growl, or just a custom look that truly reflects your style. Whatever your motivation, upgrading your exhaust system is one of the most popular and impactful modifications you can make.
At FatBoysOffroad, we understand the itch to personalize your ride. That’s why we’re diving deep into everything you need to know about upgrading your 2020 Honda Civic Si exhaust. From choosing the right system to a DIY installation guide, troubleshooting common issues, and even a 2020 Honda Civic Si exhaust care guide, we’ve got you covered. Get ready to transform your Si’s voice and unleash its full potential!
Why Upgrade Your 2020 Honda Civic Si Exhaust?
Many Si owners ask, “What are the real benefits of 2020 Honda Civic Si exhaust upgrades?” It’s more than just noise. A well-chosen aftermarket exhaust can dramatically improve your driving experience.
Enhanced Performance
The factory exhaust on your 2020 Civic Si is designed for quiet operation and broad appeal, not maximum performance. Aftermarket systems are engineered with fewer bends, larger diameter piping, and high-flow mufflers to reduce back pressure.
This allows your engine to exhale more efficiently, potentially freeing up a few extra horsepower and torque. You might notice a slightly quicker throttle response and better power delivery, especially at higher RPMs.
Signature Sound
This is often the primary reason for an upgrade. A performance exhaust can give your Si a deeper, sportier, and more aggressive tone.
You can choose from a wide range of sound profiles, from a subtle, refined growl to an ear-splitting race-car roar. Finding the perfect sound that resonates with you is key to enjoying your drive even more.
Aesthetic Appeal
Let’s not forget the visual impact. Aftermarket exhaust systems often feature larger, polished, or unique 2020 Honda Civic Si exhaust tips that significantly enhance your car’s rear end aesthetics.
Whether you prefer a burnt titanium finish, carbon fiber, or classic polished stainless steel, the right tips can complete your vehicle’s custom look.
Understanding Your Options: Types of 2020 Honda Civic Si Exhaust Systems
Navigating the world of aftermarket exhausts can be a bit overwhelming. This 2020 Honda Civic Si exhaust guide will break down the common types you’ll encounter.
Cat-Back Exhausts
A cat-back system replaces everything from the catalytic converter(s) back to the exhaust tips. This is the most common and popular upgrade for street cars.
It typically includes a new mid-pipe, muffler, and exhaust tips. Cat-back systems offer a significant improvement in sound and a modest gain in performance without altering emissions equipment, making them generally street legal.
Axle-Back Exhausts
Axle-back systems are the simplest and most affordable upgrade. They only replace the muffler and exhaust tips, from the rear axle back.
While they offer a noticeable change in sound and aesthetics, performance gains are minimal compared to a full cat-back system. They’re a great choice if your main goal is to improve sound and appearance on a budget.
Downpipes & Front Pipes
For more aggressive performance gains, especially on turbocharged engines like the Si’s 1.5L, a downpipe upgrade can be highly effective. The downpipe connects directly to the turbocharger and often replaces the restrictive factory catalytic converter with a high-flow unit or even a catless pipe (for off-road use only).
Front pipes replace the section between the downpipe and the cat-back. These modifications significantly reduce back pressure, leading to substantial power increases, but they can impact emissions and legality. Always check local regulations before installing.
Exhaust Tips
Even if you’re not ready for a full system, upgrading just your 2020 Honda Civic Si exhaust tips can make a big difference in appearance.
Many aftermarket tips are bolt-on or weld-on replacements for the factory units, offering various styles, sizes, and finishes. They won’t change performance or sound much, but they’re a quick visual win.
Choosing the Right 2020 Honda Civic Si Exhaust for Your Needs
With so many options, how do you pick the perfect exhaust? Consider these factors before making your decision.
Sound Profile & Volume
Listen to sound clips! YouTube is your friend here. Search for specific brands and models installed on a 2020 Civic Si. Pay attention to how the exhaust sounds at idle, during acceleration, and at cruising speeds to get a sense of potential drone.
Some systems are designed to be louder, others more refined. What sounds great to one person might be too obnoxious for another. Think about your daily driving habits.
Material & Durability
Exhaust systems are typically made from different grades of stainless steel or even titanium.
- 409 Stainless Steel: Entry-level, good corrosion resistance, but can show surface rust.
- 304 Stainless Steel: Excellent corrosion resistance, polished finish, and very durable. This is the most common choice for quality aftermarket exhausts.
- Titanium: Lightweight and extremely strong, but also the most expensive. Often used in high-performance or track-focused applications.
For a more sustainable 2020 Honda Civic Si exhaust choice, opting for 304 stainless steel offers excellent longevity, reducing the need for premature replacement. Some manufacturers are also exploring more eco-friendly 2020 Honda Civic Si exhaust production methods, so look for brands with transparent manufacturing processes.
Budget Considerations
Exhaust systems vary widely in price. Axle-back systems can start from a few hundred dollars, while full cat-back or titanium systems can run well over a thousand.
Factor in potential installation costs if you’re not doing it yourself. Remember, a higher price often correlates with better materials, construction, and sometimes, a more refined sound.
Legal Compliance
This is crucial. Some aftermarket exhausts, especially those that remove or modify catalytic converters (like certain downpipes), may not be legal for street use in your area. They could cause you to fail emissions tests.
Always check your local and state laws regarding vehicle modifications. Most reputable cat-back systems are designed to be street-legal and 50-state compliant, but it’s always best to verify.
DIY Installation: How to 2020 Honda Civic Si Exhaust Upgrade
Ready to get your hands dirty? Learning how to 2020 Honda Civic Si exhaust installation can be a rewarding experience. This guide covers the basics, but always refer to your specific exhaust manufacturer’s instructions.
Tools You’ll Need
- Floor jack and jack stands (or a lift)
- Socket set (10mm, 12mm, 14mm, 17mm are common)
- Ratchet and extensions
- Wrenches
- Exhaust hanger removal tool (highly recommended!)
- Penetrating oil (like WD-40 or PB Blaster)
- Torque wrench
- Safety glasses and gloves
Step-by-Step Guide (General for Cat-Back)
- Safety First: Park your Si on a flat, level surface. Engage the parking brake. Use a jack to lift the rear of the car and securely place it on jack stands. Never work under a vehicle supported only by a jack.
- Prep the Bolts: Locate the bolts connecting your factory exhaust to the catalytic converter (or downpipe). Spray them generously with penetrating oil and let it sit for a few minutes.
- Remove Hangers: Use your exhaust hanger removal tool to pry the rubber hangers off the metal pins. This can be tricky; a little lubricant on the rubber helps. Support the exhaust as you remove hangers to prevent it from falling.
- Unbolt the Factory Exhaust: Carefully unbolt the exhaust system from the catalytic converter. Once the bolts are off and all hangers are free, gently maneuver the old exhaust system out from under the car. It might be easier to cut it into sections if you’re not planning to reuse it.
- Install the New System: Begin by attaching the new exhaust to the catalytic converter using the supplied hardware. Don’t fully tighten anything yet.
- Attach Hangers & Sections: Work your way back, attaching the rubber hangers to the new exhaust sections and connecting the pipes. Ensure proper alignment and clearance from other components like heat shields or suspension parts.
- Adjust & Tighten: Once all sections are loosely in place and hanging correctly, adjust the system for optimal fitment and ensure the exhaust tips are centered in the bumper cutouts. Then, starting from the front, progressively tighten all bolts to the manufacturer’s specified torque settings.
- Final Check: Lower the car. Start the engine and listen for any leaks (you’ll hear a distinct hissing sound). If you find one, re-tighten the affected connection. Check for rattles by gently revving the engine.
Safety First!
Always prioritize safety. Working under a car can be dangerous. Ensure your jack stands are rated for your vehicle’s weight and are placed on solid points. Wear eye protection. Hot exhaust components can cause severe burns.
When to Call a Pro
If you’re uncomfortable at any point, lack the right tools, or encounter seized bolts that won’t budge, don’t hesitate to call a professional mechanic. They have the experience and equipment to get the job done safely and correctly. Sometimes, the peace of mind is worth the cost.
Common Problems with 2020 Honda Civic Si Exhaust Systems & Troubleshooting
Even with a quality installation, you might encounter issues. Here are some common problems with 2020 Honda Civic Si exhaust systems and how to address them.
Rattles & Vibrations
A new exhaust can sometimes vibrate against heat shields, suspension components, or even the chassis. This is usually due to improper alignment or insufficient clearance.
- Troubleshooting: Visually inspect the entire exhaust system from front to back while the car is off. Look for any points where the exhaust pipe is touching another component. Loosen the affected clamps/bolts, adjust the pipe slightly, and re-tighten. Sometimes, rotating the rubber hangers can help.
Exhaust Leaks
Leaks can cause a noticeable “hissing” sound, especially when the engine is cold, and can reduce performance. They often occur at connection points.
- Troubleshooting: With the engine running (cold start is best), carefully feel around the exhaust joints for escaping air. A simple trick is to spray soapy water on the connections; bubbles will indicate a leak. Re-tighten clamps or bolts, or consider using exhaust paste/sealant for stubborn leaks.
Drone Issues
Exhaust drone is an annoying, low-frequency hum or vibration felt in the cabin, typically at specific RPMs during cruising. It’s a common complaint with some aftermarket systems.
- Troubleshooting: There’s no easy fix for drone if it’s an inherent design flaw. Some options include adding a resonator (a small muffler designed to cancel specific frequencies), installing J-pipes (tuned tubes that reflect sound waves), or in extreme cases, switching to a different exhaust system.
CEL (Check Engine Light)
If your Check Engine Light comes on after an exhaust install, it’s most likely related to O2 sensors, especially if you replaced the downpipe.
- Troubleshooting: If you installed a catless downpipe, the O2 sensor might be reading insufficient catalytic converter efficiency. An O2 sensor spacer (also known as a defouler) can sometimes resolve this by moving the sensor out of the direct exhaust stream. If you installed a catted downpipe, ensure the O2 sensors are fully tightened and the wires aren’t damaged. In any case, scan the car for trouble codes to pinpoint the exact issue.
2020 Honda Civic Si Exhaust Care Guide & Maintenance
To keep your exhaust looking and sounding great for years, a little maintenance goes a long way. This 2020 Honda Civic Si exhaust care guide will help.
Regular Inspections
Periodically check your exhaust system, especially after driving on rough roads or through inclement weather. Look for:
- Loose bolts or clamps
- Cracks or holes in the piping or muffler
- Damaged or worn rubber hangers
- Corrosion, especially around welds and connections
Addressing small issues early can prevent bigger, more expensive problems down the line.
Cleaning & Protection
Your exhaust tips are constantly exposed to road grime and exhaust soot. Clean them regularly with a good automotive metal polish or chrome cleaner to maintain their shine. For matte or carbon fiber tips, follow the manufacturer’s specific cleaning recommendations.
If you live in an area with harsh winters or salted roads, consider applying an undercarriage rust preventative. While stainless steel is corrosion-resistant, road salt can still accelerate wear on clamps and hangers.
Longevity Tips
- Avoid Potholes & Speed Bumps: Be mindful of ground clearance, especially if your car is lowered. Scraping your exhaust can lead to dents, cracks, and hanger damage.
- Regular Washing: Wash your car, including the undercarriage, regularly to remove corrosive elements.
- Listen for Changes: Pay attention to any new sounds or rattles from your exhaust. Early detection of issues can save you headaches.
Frequently Asked Questions About Your 2020 Honda Civic Si Exhaust
Can upgrading my 2020 Honda Civic Si exhaust void my warranty?
Generally, a cat-back exhaust system itself won’t void your entire vehicle warranty. However, if a specific failure is directly caused by the aftermarket exhaust (e.g., a hanger breaks and damages something else), the dealership might deny a warranty claim for that specific issue. Always check with your dealership and understand the Magnuson-Moss Warranty Act.
How much horsepower will a new exhaust add to my 2020 Civic Si?
For a cat-back system, you can typically expect modest gains of 5-10 horsepower, often more noticeable in the mid to high RPM range. More aggressive setups involving downpipes can yield larger gains, but also come with more considerations regarding legality and tuning.
Will an aftermarket exhaust make my 2020 Civic Si louder inside the cabin?
Yes, almost all aftermarket exhausts will increase cabin noise, especially during acceleration. The key is to find a system that provides a desirable sound without excessive “drone” – that annoying hum at constant cruising speeds. Reading reviews and listening to sound clips can help you gauge this.
Do I need an ECU tune after installing a new 2020 Honda Civic Si exhaust?
For a cat-back or axle-back system, an ECU tune is generally not required, although a tune can always optimize performance further. If you install a downpipe that removes or significantly alters the catalytic converter, a tune is highly recommended (and often necessary) to prevent a Check Engine Light and ensure proper engine operation.
What’s the difference between a resonator and a muffler?
Both reduce exhaust noise. A muffler typically uses chambers and baffling to reflect and cancel sound waves across a broad spectrum of frequencies. A resonator is usually a straight-through pipe with perforations and packing material, designed to target and cancel specific undesirable frequencies (like drone) without significantly restricting flow.
Upgrading your 2020 Honda Civic Si exhaust is one of the most satisfying modifications you can make. It’s an investment in sound, performance, and personal expression. By understanding your options, choosing wisely, and following best practices for installation and care, you’ll enjoy a transformed driving experience that truly sets your Si apart.
Whether you’re a seasoned wrench-turner or a careful DIYer, taking the time to do it right will pay dividends in enjoyment and longevity. Don’t rush the process, always prioritize safety, and if in doubt, consult a professional.
Now, go unleash that roar and turn some heads!
Stay safe and enjoy the ride!
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