Installing an aftermarket exhaust system on a sedan is a popular modification that can significantly enhance your vehicle’s overall performance, sound, and appearance. Whether you’re aiming for a deeper exhaust note, improved horsepower, or a customized look, upgrading to a high-quality aftermarket exhaust can deliver noticeable benefits. However, the installation process requires careful attention to detail and proper tools to ensure a safe and effective fit. This comprehensive step-by-step guide will walk you through every phase of the installation, from preparation to final testing, enabling you to confidently upgrade your sedan’s exhaust system.

Benefits of Installing an Aftermarket Exhaust System

Before diving into the installation process, it’s important to understand why you might want to upgrade your sedan’s exhaust system:

  • Improved Performance: Aftermarket exhausts often feature larger diameter pipes and smoother bends that reduce backpressure, enabling the engine to breathe better and potentially increase horsepower and torque.
  • Enhanced Sound: Many enthusiasts seek a more aggressive or refined exhaust note that differs from the often-muted factory sound.
  • Weight Reduction: Some aftermarket systems utilize lighter materials like stainless steel or titanium, reducing overall vehicle weight and improving handling.
  • Custom Appearance: Polished tips or unique designs can personalize your sedan’s look.
  • Durability: High-quality aftermarket exhausts are typically more resistant to rust and corrosion compared to stock systems.

Tools and Materials Needed

To ensure a smooth installation, gather the following tools and materials before you begin:

  • Socket Set and Wrenches: Various sizes, including extensions and possibly a breaker bar for stubborn bolts.
  • Jack and Jack Stands: For safely lifting and supporting your vehicle.
  • Penetrating Oil (e.g., WD-40 or PB Blaster): To loosen rusted or seized bolts and clamps.
  • Exhaust Hanger Removal Tool: Specialized tool to safely remove exhaust hangers without damaging them.
  • New Aftermarket Exhaust System: Ensure it is specifically designed for your sedan’s make, model, and year.
  • Safety Gear: Gloves, safety goggles, and possibly a dust mask.
  • Torque Wrench: To tighten bolts to manufacturer specifications.
  • Rubber Mallet or Hammer: Useful for gently persuading parts into place.
  • Rags or Shop Towels: For cleaning components and wiping off excess penetrating oil.

Preparation Steps

Proper preparation is critical to a successful and safe installation. Follow these preparatory steps carefully:

  • Choose a Safe Work Area: Park your sedan on a flat, level surface such as a garage floor or driveway. Avoid working on slopes to prevent accidents.
  • Engage Parking Brake and Chock Wheels: This ensures the vehicle will not roll while lifted.
  • Allow Exhaust to Cool: The exhaust system can become extremely hot after running the engine. Wait at least an hour or longer to avoid burns.
  • Wear Safety Gear: Gloves to protect hands from sharp edges and goggles to shield eyes from debris.
  • Apply Penetrating Oil: Spray all bolts, clamps, and hangers on the existing exhaust system. Allow the oil to soak for 10–15 minutes to loosen rust and corrosion.
  • Gather All Tools and Parts: Organize your workspace so that all tools and the new exhaust system components are within easy reach.

Removing the Old Exhaust System

Removing the factory or old exhaust system requires patience and caution to avoid damaging surrounding components. Follow these detailed steps:

Step 1: Lift and Secure the Vehicle

Use your jack to raise the sedan high enough to comfortably work underneath. Place jack stands securely under the vehicle’s frame or designated lifting points, and gently lower the car onto the stands. Never rely solely on the jack to support the vehicle.

Step 2: Locate and Remove Fasteners

Identify the locations where the exhaust system is connected to the catalytic converter, mid-pipes, muffler, and hangers. Typically, these connections are secured with bolts, clamps, or flange nuts. Using your socket set and wrenches, carefully loosen and remove these fasteners. For bolts that are severely rusted, additional penetrating oil and some tapping with a hammer may be necessary.

Step 3: Detach Exhaust from Hangers

Using the exhaust hanger removal tool, pry the rubber hangers off the metal hooks attached to the exhaust pipes. These rubber hangers are designed to absorb vibrations but can be stiff or brittle with age. Avoid excessive force to prevent breaking them, as replacements can be costly.

Step 4: Lower and Remove Exhaust Components

With all bolts and hangers detached, carefully lower the old exhaust system from under the car. It helps to have an assistant during this step, especially if the system is heavy or awkwardly shaped. Set aside the old exhaust system for disposal or recycling.

Additional Tips for Removal

  • If the exhaust is welded or difficult to separate, you may need a reciprocating saw or angle grinder to cut through pipes. Take extreme caution to avoid damaging other components and wear proper protective equipment.
  • Inspect the catalytic converter, oxygen sensors, and other emissions components for damage or wear during removal.

Installing the New Exhaust System

With the old system removed, you’re ready to install your new aftermarket exhaust. Proper alignment and secure mounting are key to preventing leaks and rattles.

Step 1: Compare and Prepare Components

Lay out the new exhaust parts beside the old system to verify you have all necessary components and that the design matches your sedan’s configuration. Some aftermarket kits come with multiple pipes, clamps, and hardware—ensure you understand the assembly order before proceeding.

Step 2: Pre-Assemble the Exhaust System

It’s advisable to loosely connect the parts outside the vehicle to check fitment and alignment. Use supplied clamps or flanges but do not fully tighten any bolts or clamps at this stage. This flexibility allows for easier adjustment once the system is mounted under the car.

Step 3: Attach Exhaust to Catalytic Converter

Starting at the front of the system, connect the new exhaust pipe to the catalytic converter outlet. Depending on your vehicle and exhaust design, this connection may use a flange, clamp, or slip fit. Apply exhaust sealant if recommended by the manufacturer to ensure a gas-tight seal.

Step 4: Hang and Align the System

Using the exhaust hanger removal tool in reverse, slide the rubber hangers onto the metal hooks of the new exhaust. This step will require lifting the exhaust into position and may benefit from an assistant’s help. Make sure the pipes run straight and do not come into contact with the undercarriage or suspension components.

Step 5: Connect Muffler and Tailpipe

Attach the muffler and tailpipe sections, ensuring proper alignment with the rear bumper and exhaust tip placement. Adjust positioning so that the tailpipe is centered or offset as desired, without touching the bodywork to avoid vibration noise or heat damage.

Step 6: Tighten All Fasteners

Once the system is fully aligned and hanging correctly, use a torque wrench to tighten all bolts and clamps to the manufacturer’s specified torque settings. Avoid overtightening, which can strip threads or deform flanges, but ensure everything is secure enough to prevent leaks or movement.

Step 7: Inspect for Clearance and Fitment

Double-check that the exhaust system has sufficient clearance from the ground, suspension parts, brake lines, fuel lines, and other sensitive components. Small adjustments can prevent damage and ensure longevity.

Final Checks and Testing

After installation, a thorough inspection and testing phase will confirm the success of your work.

Step 1: Lower the Vehicle Safely

Remove the jack stands and carefully lower your sedan back to the ground using the jack. Ensure the vehicle is stable before proceeding.

Step 2: Visual Inspection

Inspect the entire exhaust system from underneath for any misaligned sections, loose clamps, or signs of stress. Look for gaps between flanges or clamps that might cause leaks.

Step 3: Start the Engine and Listen

Start the engine and listen closely for any unusual noises such as hissing, rattling, or loud exhaust leaks. Use a mechanic’s stethoscope or a length of hose to pinpoint any leaks along the system.

Step 4: Check for Exhaust Leaks

If you detect leaks, turn off the engine and retighten clamps or bolts as necessary. Sometimes, slight repositioning of the pipes can help achieve a better seal.

Step 5: Test Drive

Take the sedan for a short test drive, varying engine speeds and listening for rattles or changes in exhaust note. Pay attention to any vibrations or smells that might indicate leaks.

Step 6: Re-Inspect After Test Drive

After the drive, perform a final undercarriage inspection to ensure all components remain secure and no new leaks have developed.

Additional Considerations and Tips

  • Oxygen Sensors: Some aftermarket exhausts require transferring or relocating oxygen sensors. Handle these sensors carefully and ensure proper wiring connections to avoid engine errors.
  • Legal Compliance: Verify your new exhaust system complies with local emissions and noise regulations to avoid fines or vehicle inspection issues.
  • Heat Shields and Wraps: In some cases, aftermarket exhausts may lack heat shields present in stock systems. Consider installing exhaust wrap or additional heat shields to protect nearby components.
  • Break-In Period: New exhaust systems may require a break-in period where bolts are periodically rechecked and tightened.
  • Professional Help: If you encounter difficulties during installation or lack proper tools, consider consulting a professional exhaust technician to ensure safety and quality.

Conclusion

Installing an aftermarket exhaust system on your sedan is an achievable project with the right tools, preparation, and attention to detail. Beyond the technical steps, the upgrade provides tangible improvements in your vehicle’s sound, performance, and aesthetics. By following this comprehensive guide, you can confidently remove the old exhaust system and install your new aftermarket setup safely and effectively. Remember to prioritize safety, consult your vehicle’s manual for specifics, and reach out to professionals if needed. Enjoy the enhanced driving experience that a quality aftermarket exhaust system delivers!