Upgrading your Mitsubishi Lancer Ralliart with aftermarket headers is a popular modification that can transform your vehicle’s performance and auditory character. Headers replace the factory exhaust manifold, providing a more efficient path for exhaust gases to leave the engine. By reducing exhaust backpressure and improving scavenging, aftermarket headers can increase horsepower, torque, throttle response, and even fuel efficiency when paired with the right supporting modifications. Additionally, headers often impart a deeper and more aggressive exhaust note that enhances the driving experience.

However, installing aftermarket headers is not simply a bolt-on upgrade; it requires careful preparation, attention to detail during installation, and post-installation tuning considerations to ensure optimal performance and reliability. In this comprehensive guide, we’ll walk through everything you need to know to successfully install aftermarket headers on your Mitsubishi Lancer Ralliart, from initial preparations to fine-tuning after installation.

Understanding the Benefits of Aftermarket Headers

The stock exhaust manifold on the Mitsubishi Lancer Ralliart is designed primarily for emissions control, cost efficiency, and noise reduction rather than maximum performance. Aftermarket headers improve upon these aspects by:

  • Improving Exhaust Flow: Headers typically feature individual tubes for each cylinder that merge smoothly, minimizing restrictions and allowing exhaust gases to exit more freely.
  • Enhancing Scavenging: The design promotes better evacuation of exhaust gases from the cylinders, helping the engine breathe more efficiently during the intake stroke.
  • Increasing Power: By reducing backpressure and improving exhaust flow, headers can unlock additional horsepower and torque, especially in the mid to high RPM range.
  • Improving Sound Quality: Headers often produce a more aggressive and sportier exhaust tone compared to stock manifolds.
  • Reducing Engine Heat: High-quality headers made from materials like stainless steel or ceramic-coated steel can better dissipate heat, protecting engine components and improving longevity.

While these benefits are enticing, maximizing them requires a proper installation process to prevent issues such as leaks, fitment problems, or damage to other components.

Preparation Before Installing Aftermarket Headers

Proper preparation is the foundation of a successful header installation. Follow these steps to get ready:

Gather the Right Tools and Equipment

Having the necessary tools on hand before you begin will make the installation smoother. Commonly needed tools include:

  • A complete socket set (both metric and standard sizes)
  • Combination wrenches
  • Torque wrench for precise bolt tightening
  • Penetrating oil (such as PB Blaster or Liquid Wrench) to loosen rusted or stuck bolts
  • Jack stands and/or a hydraulic lift to safely raise the vehicle
  • Safety equipment like gloves and eye protection
  • New gaskets and hardware (often supplied with the header kit)
  • Shop towels and degreaser for cleaning surfaces

Prepare Your Workspace

Choose a well-lit, flat, and well-ventilated workspace. Working on a level surface is important for safety and ease of access. Ensure you have enough room around the vehicle to maneuver tools and parts freely.

Safety First: Disconnect the Battery and Cool the Engine

Before beginning, disconnect the negative battery terminal to prevent accidental electrical shorts or shocks. Since you will be working on the exhaust system, allow the engine to cool completely—this can take several hours—to avoid burns from hot manifold surfaces.

Review the Header Kit Instructions

Every aftermarket header kit may have unique installation requirements, flange designs, or hardware. Thoroughly read the manufacturer’s instructions and any included tips before starting. This will help you avoid surprises and understand the steps involved.

Step-by-Step Installation Guide

Installing aftermarket headers on your Mitsubishi Lancer Ralliart involves several critical steps. Take your time and work systematically to ensure the best results.

1. Remove the Stock Exhaust Manifold

Begin by detaching the stock manifold from the cylinder head and the exhaust system. This can be challenging due to tight spaces and rusted bolts. Use penetrating oil liberally on all bolts and let it soak in for 10-15 minutes to ease removal. If bolts are severely corroded, use caution to avoid snapping them.

Remove any heat shields or components obstructing access. Label or photograph bolt locations and connections for reference during reassembly.

2. Clean the Cylinder Head Exhaust Ports and Mounting Surface

Once the old manifold is removed, thoroughly clean the mating surface on the cylinder head. Use a gasket scraper or razor blade to remove old gasket material, carbon deposits, and debris. A clean, smooth surface is essential to ensure a proper seal and prevent exhaust leaks.

3. Test Fit the New Headers

Before installing new gaskets or tightening bolts, test fit the headers to check clearance with other engine components, wiring, brake lines, and the chassis. Pay attention to any potential interference and adjust as necessary, such as repositioning wiring harnesses or brackets.

4. Install New Gaskets and Position the Headers

Place the provided gaskets carefully against the cylinder head. High-quality gaskets that come with your kit or recommended by the manufacturer help prevent leaks and maintain performance. Align the headers with the bolt holes and hand-thread the bolts to hold them in place.

5. Torque the Header Bolts Evenly

Using a torque wrench, tighten the header bolts in a crisscross or manufacturer-recommended sequence. This ensures even pressure across the flange and prevents warping or leaks. Be sure to follow the torque specifications provided in the header kit instructions or your vehicle’s service manual.

6. Reconnect the Rest of the Exhaust System

Reconnect the mid-pipe or downpipe to the headers using supplied hardware or existing clamps. Inspect any oxygen sensors or wiring and reinstall them as needed. Use anti-seize compound on oxygen sensor threads to ease future removal.

7. Double Check All Connections and Clearances

Inspect all bolts and connections to confirm they are secure. Verify that the headers and connected exhaust components do not contact any moving parts, wiring, or components sensitive to heat damage.

Post-Installation Procedures and Considerations

Inspect for Exhaust Leaks

Start the engine and listen carefully for any signs of exhaust leaks such as hissing or tapping noises near the header flanges. You can also feel around the joints for escaping gases (with care to avoid burns). If leaks are detected, re-torque bolts or replace gaskets as needed.

Engine Tune for Optimal Performance

Because headers change exhaust flow and backpressure, it’s often necessary to recalibrate the engine’s fuel and ignition settings to maximize gains and avoid issues such as running lean or triggering check engine lights. Consider a professional ECU tune or using a handheld tuner designed for the Lancer Ralliart to adjust parameters like air-fuel ratio and ignition timing.

Monitor Engine Performance and Emissions

After installation and tuning, monitor your engine’s performance closely. Pay attention to fuel economy, throttle response, and any abnormal noises or behaviors. Also, be aware of local emissions regulations, as aftermarket headers may affect compliance and could require catalytic converter upgrades or additional emissions equipment.

Heat Management

Headers can increase under-hood temperatures. To protect nearby components and maintain engine bay temperatures, consider installing heat wraps or ceramic coatings on the headers. These treatments reduce radiant heat and can improve durability.

Additional Tips for a Successful Header Upgrade

  • Use Anti-Seize on Bolts: Applying anti-seize compound on header bolts during assembly helps prevent galling and makes future removal easier.
  • Replace Exhaust Hardware: Old bolts, nuts, and clamps can corrode or weaken over time; replace them with high-quality stainless steel components if possible.
  • Plan for Catalytic Converter Compatibility: Ensure your header setup works with existing emissions equipment or upgrade to compatible high-flow catalytic converters if necessary.
  • Consult Experienced Installers: If you’re unsure about any step, seek advice from professional mechanics or Mitsubishi enthusiast communities who have experience with Lancer Ralliart header installations.
  • Document Your Modifications: Keep detailed records of parts used, torque specs, and tuning adjustments for future reference or resale value.

Common Challenges and How to Overcome Them

Stuck or Broken Bolts

One of the most common issues during header removal is seized or broken bolts due to heat cycles and corrosion. To avoid this:

  • Apply penetrating oil well in advance and let it soak thoroughly.
  • Use proper tools such as impact sockets or breaker bars for leverage.
  • If a bolt breaks, use specialized extraction tools or seek professional help to avoid damaging the cylinder head.

Fitment Issues

Aftermarket headers may sometimes have fitment challenges due to manufacturing tolerances or differences between models. If you encounter tight clearances or interference:

  • Check for bent flanges or tubes and carefully adjust using heat or bending tools if feasible.
  • Relocate or modify brackets, wiring, and hoses to create clearance.
  • Verify that you have the correct header kit for your specific year and engine variant of the Lancer Ralliart.

Check Engine Lights or Sensor Errors

Upgrading headers can affect oxygen sensor readings and trigger warning lights. To address this:

  • Use high-quality oxygen sensors compatible with your new headers.
  • Consider installing wideband sensors and a piggyback engine management system for precise tuning.
  • Perform a proper ECU tune to recalibrate sensor inputs.

Conclusion

Installing aftermarket headers on your Mitsubishi Lancer Ralliart is a rewarding upgrade that can deliver noticeable gains in power, torque, and exhaust sound. With thorough preparation, careful installation, and proper tuning, you can unlock your vehicle’s full potential while maintaining reliability and drivability.

Remember that patience and attention to detail during the installation process are key to avoiding common pitfalls. Take time to understand the specific requirements of your header kit, protect your engine with quality gaskets and proper torque, and always verify clearances and connections before firing up your engine.

With these tips and best practices, your Lancer Ralliart will not only perform better but also provide a more engaging and thrilling driving experience. Enjoy the enhanced power and distinctive sound that aftermarket headers bring to your Mitsubishi!