Exhaust For 2017 Honda Civic Si – Unleash Performance, Sound

Ever felt that your 2017 Honda Civic Si, while fantastic, could use a little more roar? You’re not alone. Many enthusiasts agree that upgrading the exhaust for 2017 Honda Civic Si is one of the most satisfying modifications you can make.

It’s not just about turning heads with a deeper, more aggressive note; a well-chosen exhaust system can also unlock hidden horsepower and torque, improve throttle response, and even shed a few pounds from your ride. If you’re looking to transform your Si from a great daily driver into an exhilarating street machine, you’ve come to the right place.

In this comprehensive guide, we’ll dive deep into everything you need to know about choosing, installing, and maintaining the perfect exhaust system for your 2017 Civic Si. We’ll cover the different types of systems, what to look for, how to tackle the installation yourself, and even how to keep it sounding great for years to come. Get ready to give your Si the voice it deserves!

Why Upgrade Your Exhaust for 2017 Honda Civic Si?

Upgrading the exhaust system on your 2017 Honda Civic Si offers a multitude of benefits beyond just a louder car. It’s a holistic enhancement that touches on performance, aesthetics, and the overall driving experience.

Enhanced Performance

The factory exhaust system is designed for quiet operation and broad appeal, often restricting exhaust gas flow. An aftermarket exhaust, especially a cat-back or turbo-back system, typically features wider piping and fewer restrictive bends.

Increased Horsepower and Torque: By reducing backpressure, the engine can “breathe” more easily, allowing spent gases to exit faster. This often translates to noticeable gains in both horsepower and torque, especially in the mid to high RPM range.
Improved Throttle Response: A less restrictive exhaust can lead to quicker engine response when you hit the gas, making your Si feel more eager and agile.
Weight Reduction: Many aftermarket systems are made from lighter materials like stainless steel or titanium, shedding crucial pounds compared to the stock setup. This can subtly improve handling and acceleration.

Signature Sound

This is arguably the most common reason drivers seek an upgraded exhaust for 2017 Honda Civic Si. The stock Si sounds good, but it’s often too subdued for enthusiasts.

Deeper, More Aggressive Tone: Aftermarket mufflers are tuned to produce a richer, sportier sound. You can choose from a wide range of sound profiles, from subtly enhanced to aggressively raw.
Reduced Drone: High-quality systems are engineered to minimize unpleasant cabin drone at cruising speeds, giving you the best of both worlds – aggressive when you want it, comfortable when you don’t.

Aesthetic Appeal

Let’s face it, a great-looking exhaust can significantly enhance your Si’s rear profile.

Stylish Tips: Aftermarket exhausts often come with larger, more aesthetically pleasing exhaust tips, available in various finishes like polished, burnt titanium, or carbon fiber. These tips can fill out the bumper cutouts better and give your Si a more aggressive, customized look.
Overall Visual Enhancement: A gleaming new exhaust system underneath your car is a clear sign of a performance-oriented vehicle.

Types of Exhaust Systems: Finding Your Perfect Match

When considering an exhaust for 2017 Honda Civic Si, you’ll encounter a few main types of systems. Understanding the differences is crucial for making an informed decision that aligns with your goals and budget.

Axle-Back Systems

This is the simplest and often most affordable upgrade. An axle-back system replaces only the muffler section from the rear axle backward, including the exhaust tips.

Pros: Easiest to install, most budget-friendly, primarily changes exhaust sound and tip aesthetics.
Cons: Offers minimal performance gains as it retains the most restrictive parts of the OEM exhaust (catalytic converter, resonator, and mid-pipe).
Best For: Drivers primarily seeking a sound upgrade and improved looks without major performance changes or complex installation.

Cat-Back Systems

A cat-back system replaces everything from the catalytic converter back to the exhaust tips. This typically includes a new mid-pipe, resonator (or resonator delete), muffler, and tips.

Pros: Significant sound improvement, noticeable performance gains due to less restrictive piping, wider range of sound profiles and tip options.
Cons: More expensive and complex to install than axle-back systems, but still generally DIY-friendly.
Best For: Enthusiasts looking for a balance of performance, sound, and aesthetic upgrades without touching emission-critical components. This is often the most popular choice for the 2017 Civic Si.

Full Turbo-Back Systems

A turbo-back system replaces the entire exhaust system from the turbocharger outlet back, including the downpipe, catalytic converter (often with a high-flow or cat-less option), mid-pipe, muffler, and tips.

Pros: Maximum performance gains, especially when paired with a tune, most aggressive sound.
Cons: Most expensive, most complex to install, may require a custom tune, and often involves replacing or removing the catalytic converter, which can have legal and emissions implications depending on your region.
Best For: Serious performance seekers and track enthusiasts who are willing to invest in a full system and potentially a tune to extract the most power from their Si. Be mindful of local regulations regarding catalytic converters.

Materials Matter: Stainless Steel vs. Titanium

The material of your exhaust system greatly impacts its durability, weight, and cost.

304 Stainless Steel: This is the most common material for aftermarket exhausts. It offers excellent corrosion resistance, durability, and a good balance of weight and cost. It’s a fantastic long-term solution.
Titanium: Far lighter than stainless steel, titanium systems are often found on high-end, performance-focused exhausts. They are incredibly strong for their weight but come at a significantly higher price point.
Aluminized Steel: While cheaper, aluminized steel is less resistant to corrosion and typically has a shorter lifespan, making it less ideal for the longevity enthusiasts expect from an exhaust for 2017 Honda Civic Si.

Choosing the Best Exhaust for Your 2017 Honda Civic Si

Selecting the right exhaust involves more than just picking a brand. It’s about balancing several factors to achieve your ideal setup. Here are some exhaust for 2017 Honda Civic Si tips to guide your decision.

Sound Profile & Drone

Sound is subjective, but crucial. Research sound clips online, but remember that videos don’t always capture the true in-person experience.

Aggressive vs. Mellow: Do you want a race-car roar or a refined, sporty note? Brands like Remark and Borla often offer more aggressive tones, while systems from HKS or GReddy might be a bit more subdued but still performance-oriented.
Minimize Drone: “Drone” is an undesirable, resonant hum inside the cabin, typically at cruising RPMs. High-quality systems are engineered to mitigate drone through resonator design or Helmholtz chambers. Read reviews specifically addressing drone for any system you consider.

Performance Gains

While most cat-back systems offer modest gains (5-15 hp), some are designed with more emphasis on flow efficiency. Full turbo-back systems, especially with a tune, will yield the most significant power increases.

Dyno Charts: Look for manufacturers who provide dyno charts showing before-and-after results. This gives you a realistic expectation of performance benefits.
Future Mods: If you plan on further engine modifications (e.g., turbo upgrade, tuning), consider an exhaust system that can support higher power levels.

Budget Considerations

Exhaust systems for the 2017 Civic Si can range from a few hundred dollars for an axle-back to well over a thousand for a premium cat-back or turbo-back system.

Entry-Level: Axle-backs like those from Remark or certain budget-friendly brands are a good starting point.
Mid-Range: Most popular cat-back options from brands like Borla, MagnaFlow, Invidia, and AWE Tuning fall into this category.
Premium: Full titanium systems or highly engineered cat-backs from brands like HKS or Spoon Sports will be at the higher end.

Legalities & Emissions

This is a critical consideration, especially for turbo-back systems.

Catalytic Converters: Removing or modifying your catalytic converter is illegal in most regions and will cause your car to fail emissions testing. If you opt for a downpipe, ensure it includes a high-flow catalytic converter that is CARB-compliant if required in your state (e.g., California).
Sound Ordinances: Some areas have strict noise regulations. While most reputable aftermarket exhausts are designed to be street-legal, extremely loud systems could attract unwanted attention.
Check Engine Light (CEL): Replacing the catalytic converter, even with a high-flow unit, can sometimes trigger a CEL due to changes in O2 sensor readings. This often requires an ECU tune to resolve.

DIY Installation: How to Exhaust for 2017 Honda Civic Si

Installing an exhaust for 2017 Honda Civic Si is a common DIY project for weekend mechanics. With the right tools and a bit of patience, you can save on labor costs and gain a satisfying sense of accomplishment. Always prioritize safety!

Tools You’ll Need

Before you begin, gather all your tools. Having everything ready saves time and frustration.

Socket wrench set (metric, usually 12mm, 14mm, 17mm)
Extension bars for your wrench
Jack and jack stands (or a lift)
Wheel chocks
Penetrating oil (e.g., WD-40, PB Blaster)
Exhaust hanger removal tool (highly recommended, though a pry bar can work)
Rubber mallet
Safety glasses and gloves
Torque wrench (for proper re-installation)
New exhaust gaskets (often included with aftermarket systems, but confirm)

Safety First!

Never compromise on safety when working under a vehicle.

Stable Surface: Ensure your car is on a flat, level, and stable surface.
Securely Jacked: Always use sturdy jack stands to support the vehicle. Never rely solely on a jack.
Wheel Chocks: Place wheel chocks on the wheels that remain on the ground.
Cool Exhaust: Make sure the exhaust system is completely cool before you start. Hot metal can cause severe burns.

Step-by-Step Guide

This guide assumes a cat-back installation, the most common upgrade for the Si.

Prepare the Vehicle:
- Park your Civic Si on a flat surface.
- Engage the parking brake.
- Chock the front wheels.
- Jack up the rear of the car and place it securely on jack stands. Ensure it’s stable.
Loosen Existing Exhaust:
- Locate the bolts connecting the stock exhaust system to the catalytic converter (or downpipe). These are usually near the middle of the car.
- Apply penetrating oil to all bolts and exhaust hangers. Let it soak for a few minutes.
- Using your socket wrench, carefully loosen these bolts. They might be stubborn due to rust.
- Locate all the exhaust hangers (rubber isolators) that support the exhaust pipe.
Remove the Old Exhaust:
- Starting from the rear, use the exhaust hanger removal tool (or a pry bar) to pop the rubber hangers off the metal pins. This can be tricky.
- Once all hangers are free and the front bolts are loose/removed, carefully lower and remove the stock exhaust system. It might come out in a few pieces depending on its design. This is easier with a helper.
Install the New Exhaust:
- Begin by installing the front-most pipe of your new cat-back system (the mid-pipe).
- Use new gaskets and loosely attach the bolts to the catalytic converter/downpipe. Don’t tighten them yet.
- Attach the pipe to its corresponding rubber hangers.
- Continue working backward, connecting each section (resonator, muffler, tips) and attaching them to their hangers. Leave all bolts loose for now.
- Once all sections are in place and supported by hangers, align the exhaust tips to your desired position.
- Starting from the front connection, gradually tighten all bolts. Work your way back, ensuring all connections are snug and there are no gaps.
- Pro Tip: A little anti-seize compound on the bolts can make future removal easier.

Post-Installation Checks

Once everything is tightened, perform these checks:

Double-Check All Bolts: Ensure every bolt is torqued to the manufacturer’s specifications.
Hanger Clearance: Check that the exhaust pipes have adequate clearance from the chassis, suspension, and heat shields. There should be no rubbing.
Start the Car: Start the engine and listen for any exhaust leaks (a hissing sound). You can sometimes feel leaks with your hand (carefully, as it gets hot quickly) or by spraying soapy water around connections and looking for bubbles.
Test Drive: Take a short, careful test drive. Listen for any rattles, vibrations, or unusual noises. Ensure there’s no drone at typical cruising speeds.

Common Problems & Troubleshooting Your New Exhaust

Even with careful installation, issues can arise. Knowing how to identify and address common problems with exhaust for 2017 Honda Civic Si will save you headaches.

Exhaust Leaks

A leak can sound like a hiss, tick, or even a whistle, and it reduces performance and alters the sound.

Cause: Improperly tightened clamps/bolts, damaged gaskets, or a crack in the pipe.
Fix: Check all connections, tighten clamps, replace worn or damaged gaskets. For cracks, professional welding may be required.

Annoying Drone

While some drone is expected with aggressive systems, excessive drone can be unbearable.

Cause: Poor system design, improper installation leading to vibrations, or simply a sound profile that’s too aggressive for your preference.
Fix: Ensure proper alignment and clearance. Consider adding a resonator or a J-pipe (Helmholtz resonator) if your system doesn’t have one. Some drivers add sound deadening material to the trunk area.

Poor Fitment

If the exhaust hangs too low, rubs, or the tips are crooked, it’s a fitment issue.

Cause: Manufacturing defect, incorrect part for your vehicle, or improper installation.
Fix: Re-check all hangers and connections. Loosen all bolts, adjust the pipes, and re-tighten. If it’s a persistent issue, contact the manufacturer or a professional installer.

Check Engine Light (CEL)

A CEL can be alarming, especially after an exhaust upgrade.

Cause: Most commonly, this occurs if you’ve replaced the catalytic converter with a high-flow or cat-less downpipe. The O2 sensors might detect an efficiency difference.
Fix: If you replaced the cat, you’ll likely need an ECU tune to “turn off” the CEL associated with O2 sensor readings. Sometimes, an O2 sensor spacer can temporarily help, but tuning is the proper solution. If you only installed a cat-back, a CEL is rare and indicates a different issue, possibly a loose O2 sensor wire if one was disturbed.

Maintaining Your New Exhaust System

To ensure your investment lasts and continues to perform optimally, proper care is essential. Following these exhaust for 2017 Honda Civic Si care guide practices will extend its lifespan and maintain its appearance.

Regular Inspections

Make it a habit to periodically inspect your exhaust system.

Visual Checks: Look for any signs of rust, cracks, loose hangers, or exhaust leaks. Pay attention to welds and connection points.
Sound Changes: Any sudden changes in exhaust note could indicate a developing leak or a loose component.
Underbody Scrapes: If you drive over rough terrain or speed bumps frequently, check for scrapes or dents on the underside of the pipes.

Cleaning & Protection

Keep your exhaust tips looking pristine and protect the entire system.

Tip Cleaning: Use a metal polish specifically designed for exhaust tips to remove carbon buildup and restore shine. A fine steel wool or dedicated metal cleaner can tackle tougher stains.
Underbody Wash: Regularly wash the underside of your car, especially after driving on salted roads in winter. This helps remove corrosive elements that can lead to rust.
Ceramic Coatings: For those looking for extra protection, some automotive detailers offer ceramic coatings for exhaust components, which can repel dirt and make cleaning easier.

Addressing Rust & Corrosion

Even stainless steel can develop surface rust over time, especially in harsh climates.

Surface Rust: Small spots of surface rust on stainless steel can often be removed with a metal polish or a fine abrasive pad.
Preventative Measures: Consider rust-proofing sprays for areas that are prone to corrosion, particularly around hangers and clamps.
Sustainable & Eco-Friendly Considerations: Opting for high-quality stainless steel (like 304 grade) ensures a longer lifespan, meaning less waste and fewer replacements over the years. This aligns with sustainable exhaust for 2017 Honda Civic Si practices. A durable system is inherently more eco-friendly than one that needs frequent replacement. When choosing an exhaust, consider the manufacturing processes and the longevity of the materials used.

Frequently Asked Questions About 2017 Honda Civic Si Exhausts

How much horsepower does an exhaust add to a 2017 Civic Si?

For a cat-back exhaust, you can typically expect gains of 5-15 horsepower and similar torque figures. Full turbo-back systems, especially with a proper ECU tune, can yield more significant gains, sometimes in the 20-30+ horsepower range.

Will installing an aftermarket exhaust void my warranty?

Generally, no. Under the Magnuson-Moss Warranty Act, a manufacturer cannot void your entire warranty simply because you installed an aftermarket part. They must prove that the aftermarket part directly caused the failure of a warrantied component. However, if your exhaust causes an issue with, say, your turbocharger or engine, that specific repair might not be covered. Always check with your dealership for their specific policy.

What’s the difference between a resonator and a muffler?

Both reduce sound, but they do it differently. A muffler uses baffles, chambers, and sound-absorbing materials to quiet exhaust noise across a broad frequency range. A resonator is typically a straight-through pipe with perforations and an outer shell, designed to cancel out specific unwanted sound frequencies, particularly drone, by creating opposing sound waves.

Can I install a new exhaust myself, or should I go to a professional?

Many DIYers with basic mechanical skills and tools can successfully install an axle-back or cat-back exhaust. The process typically involves unbolting and unhanging the old system and reversing the process for the new one. However, if you’re uncomfortable working under a car, lack the proper tools, or are installing a complex turbo-back system, professional installation is always a safe bet.

Are louder exhausts always better for performance?

Not necessarily. While a less restrictive exhaust often leads to more noise and better performance, simply making an exhaust louder doesn’t guarantee more power. Poorly designed loud exhausts can still have restrictive bends or introduce unwanted drone. The best performance exhausts are engineered for optimal flow and sound, not just maximum decibels.

Upgrading the exhaust for 2017 Honda Civic Si is a fantastic way to personalize your ride, enhance its performance, and truly unleash its sporty character. Whether you’re chasing horsepower, a head-turning sound, or a more aggressive aesthetic, there’s an exhaust system out there for you.

Remember to choose wisely, prioritize safety during installation, and perform regular maintenance to ensure your investment lasts. With a bit of elbow grease and the right setup, you’ll be enjoying every drive in your Si even more. Stay safe and happy wrenching!

Author
Recent Posts

Thomas Corle

Founder & Automobile expert at FatBoysOffroad

Automobile expert and off-road enthusiast, sharing in-depth knowledge of vehicles, gear, and adventures. Helping readers make smart decisions and enjoy the thrill of off-roading safely and confidently.