Upgrading your vehicle’s exhaust system with a Mishimoto 3.3T Performance Exhaust System is one of the most effective ways to unlock additional horsepower, improve throttle response, and give your car a deep, aggressive tone. The precision engineering that goes into each Mishimoto component ensures a seamless fit and noticeable performance gains, but a successful installation depends on careful preparation and attention to detail. This guide walks you through every phase of the process, from selecting the right tools to performing the final sound check, so you can complete the job with confidence and enjoy the full benefits of your new exhaust.

Tools and Materials Needed

Before you begin, gather all the equipment that will make the installation smooth and safe. Having the correct tools on hand eliminates unnecessary trips to the hardware store and reduces the risk of damaging components. For this installation you will need:

  • A full metric socket set (including extensions and a ratchet)
  • Combination wrench set (10mm, 12mm, 14mm, 17mm recommended)
  • Floor jack and two heavy-duty jack stands
  • Exhaust hanger removal tool (or a suitable pry bar with a hook)
  • Penetrating lubricant (e.g., WD‑40 or PB Blaster)
  • Safety glasses and mechanic’s gloves
  • Torque wrench (capable of reading in ft‑lbs)
  • Rubber mallet (for stubborn hangers)
  • Optional: oxygen sensor socket, anti-seize compound, and a second person for alignment
  • Mishimoto 3.3T Performance Exhaust System (including all hardware and gaskets)

If you do not already own a quality exhaust hanger tool, it is a worthwhile investment: it saves time and prevents the rubber isolators from tearing. You can also use a lubricant like PB Blaster on corroded bolts to ease removal.

Preparation

Safety and workspace preparation directly affect the quality of the installation. Park your vehicle on a level, solid surface such as a concrete garage floor. Allow the engine and exhaust system to cool completely — hot components can cause severe burns and may make bolts harder to remove. Disconnect the negative battery terminal to avoid any electrical shorts while working near the exhaust’s oxygen sensors. Gather your tools within arm’s reach and lay out the Mishimoto exhaust components to verify everything is included: the main piping, muffler or resonator sections, hangers, clamps, and any gaskets. Inspect each piece for shipping damage and read the included instruction sheet once before starting.

Step 1: Raise the Vehicle Safely

Position the jack under the vehicle’s designated front jacking point (consult your owner’s manual). Lift the vehicle until the wheels are several inches off the ground, then place jack stands under the factory pinch‑weld jacking points or frame rails. Lower the vehicle onto the stands and give it a firm shake to confirm stability. Never rely solely on a jack while working underneath — a car can fall without warning. For extra safety, chock the rear wheels.

Once the vehicle is secure, you will have ample clearance to access the exhaust system from the manifold back to the rear muffler.

Step 2: Remove the Stock Exhaust System

2.1 Disconnect the Oxygen Sensors

If your vehicle has oxygen sensors located in the exhaust piping, unplug their electrical connectors before removing any bolts. Use an oxygen sensor socket or a 22mm wrench to carefully unscrew each sensor from the pipe. Place the sensors aside in a clean area — they will be re‑installed into the Mishimoto system if compatible.

2.2 Unbolt the Exhaust from the Manifold

Using a socket and ratchet, remove the bolts or nuts that attach the downpipe or front pipe to the exhaust manifold. These fasteners are often tight; apply penetrating lubricant and allow it to sit for five minutes if needed. Support the exhaust from underneath to prevent it from dropping suddenly.

2.3 Remove the Exhaust Hangers

Stock exhaust hangers are rubber isolators that hold the piping to the chassis. Use an exhaust hanger removal tool to pull each hanger off its metal stud. If the rubber feels stiff, spray a little lubricant to ease removal. In some cases you may need to use a pry bar with a hook — be careful not to damage the metal hanger studs. Label the hangers if they appear different in size (front vs. rear).

2.4 Separate and Remove the Factory Exhaust Sections

Slide the stock exhaust sections apart at their slip joints or unbolt them at flanges. Lower each section carefully, taking note of the routing and the positions of any heat shields. A helper is useful here to avoid bending the piping against the undercarriage. Once the stock exhaust is completely free, place it out of the work area.

Tip: While the exhaust is off, inspect the manifold studs and surrounding area for corrosion or damage. Clean the manifold flange surface with a wire brush if necessary.

Step 3: Install the Mishimoto Exhaust System

3.1 Prepare the Connections

Check the Mishimoto kit for gaskets — place a new gasket between the manifold and the downpipe flange. Applying a thin layer of anti‑seize to the manifold studs will make future removal easier and prevent galling. Thread the supplied hardware loosely at first; you will tighten everything to spec later.

3.2 Assemble the System Start to Finish

Begin at the engine side: attach the downpipe or front section to the manifold flange. Hand‑tighten the nuts or bolts. Next, move rearward and connect the intermediate pipe or mid‑section, using the supplied clamps or flanges. Work your way toward the muffler and tailpipe. Each connection should be assembled loosely so you can adjust the overall position of the exhaust and ensure it hangs evenly.

3.3 Route the Piping with Care

Watch for clearance around the driveshaft, axles, suspension arms, and underbody braces. The Mishimoto system is designed to fit the specific chassis, but you may need to tweak the pipe angles slightly by rotating them in their joints. Verify that the tailpipe exits in the correct location and is not touching the bumper or frame.

Step 4: Secure the Hangers

Once the exhaust is loosely assembled, install the rubber hangers that came with the Mishimoto kit or reuse the factory hangers if they are in good condition. Start at the frontmost hanger and work toward the rear. Push each hanger fully onto its metal stud. Using a rubber mallet can help seat stubborn hangers, but avoid hitting the exhaust piping directly. After all hangers are in place, check that the exhaust is supported evenly and does not sag. Adjust the pipe positions as needed — typically by twisting the piping at the slip joints — to align the hangers without binding.

Step 5: Tighten All Bolts to Spec

Now is the time to create the final, leak‑free seal. Begin at the manifold connection and tighten the bolts or nuts in a cross‑pattern to the torque specified in the Mishimoto instructions (usually 30–40 ft‑lbs for manifold flange bolts). Work rearward, tightening each flange clamp or bracket to the recommended value. If your kit uses band clamps, tighten them just enough to prevent rotation but not so much that they crush the pipe. Use a torque wrench to ensure consistency — overtightening can strip threads or deform flanges, while undertightening leads to exhaust leaks and noise.

After tightening all connections, go back and re‑check each bolt once more. It is common for loosely assembled joints to shift as you tension the hangers.

Step 6: Lower the Vehicle and Perform a Clearance Inspection

With the exhaust fully bolted and hanging in its final position, remove the jack stands and lower the vehicle to the ground. Before starting the engine, visually inspect the entire exhaust system from side to side and from front to back. Confirm that there is at least 1 inch of clearance around all moving parts, heat‑sensitive components, and the bottom of the chassis. Turn the steering wheel lock‑to‑lock to check for interference with the front half‑shafts or steering linkage. If anything makes contact, loosen the relevant connections and reposition the piping.

Reconnect the battery negative terminal and plug in the oxygen sensors (if you removed them). Make sure the sensor wires are not routed too close to hot exhaust surfaces; zip‑tie them away if necessary.

Step 7: Start the Engine and Test for Leaks

7.1 Initial Startup

Start the engine and let it idle. Immediately listen for any abnormal hissing, ticking, or loud escaping air that would indicate a leak at the manifold or flange joints. Move around the vehicle and place your hand near each connection (without touching hot metal) to feel for puffs of exhaust gas. A shop rag or a piece of cardboard held near the joints can also reveal leaks.

7.2 Re‑Torque After Heat Cycle

Allow the engine to reach operating temperature, then turn it off and let the exhaust cool enough to handle. Re‑tighten all the bolts again while the system is still warm — this compensates for the expansion and contraction that occurs during the first heat cycle. This step is critical for achieving a lasting seal and preventing blow‑outs later.

7.3 Test Drive and Final Check

Take the vehicle for a short, moderate‑speed drive (5–10 miles) to allow the exhaust to settle into its natural position. After the drive, park on a level surface and inspect the system again: look for any new leaks, check that the hangers have not slipped, and listen for rattles or boominess that might indicate contact with the underbody. If everything sounds clean and feels solid, the installation is complete.

Post‑Installation Tips and Maintenance

The Mishimoto exhaust system is built to last, but taking a few extra precautions will maximize its lifespan:

  • Break‑in period: Some stainless steel systems take 200–500 miles to fully “settle.” Minor changes in sound and tone are normal. Avoid full‑throttle pulls until you have confirmed that all clamps and hangers remain tight.
  • Periodic bolt checks: After the first 100 miles, re‑torque the manifold flange bolts and all band clamps. Thermal cycles can cause fasteners to loosen slightly.
  • Cleaning: Wash the exhaust piping with mild soap and water to remove road salt or dirt. Avoid harsh abrasives that could scratch the finish. A high‑temperature spray wax can help maintain the polished look.
  • Watch for CEL: If your vehicle is equipped with downstream oxygen sensors, a cat‑back system typically does not trigger a check engine light. However, if you have removed or modified the catalytic converter (as part of a full turbo‑back setup), you may need a tune or a defouler to prevent a CEL. Consult with a professional tuner if needed.

Conclusion

Installing a Mishimoto 3.3T Performance Exhaust System is a hands‑on project that rewards you with a richer exhaust note, improved horsepower, and a custom look under your car. By following this expanded guide — from safety preparation through the final test drive — you can perform the installation with the same care and precision as a professional shop. Take your time on each step, use the correct tools, and do not skip the re‑torquing procedure after the first heat cycle. The effort is well worth the result: a performance upgrade that you installed yourself and can enjoy every time you turn the key.

For more detailed specifications or to order replacement hardware, visit Mishimoto’s official website. If you get stuck during the installation, forums such as Genesis Owners often have model‑specific advice from other enthusiasts who have performed the same upgrade.