Invidia Q300 Exhaust Honda Civic Si Coupe FG2 K20Z3 (2006-2011) Catback w/ Polished or Titanium Blue Tip

Fitment Information

• Honda Civic Si Coupe FG2 K20Z3 2.0L 8th Gen (2006, 2007, 2008, 2009, 2010, 2011)
• Coupe only, does not fit Si Sedan

Fitment Note: Coupe FG2 body style only. The Si Sedan (FA5) uses a different rear bumper exit and needs separate SKUs (HS06HC4G3S for polished, HS06HC4G3T for titanium blue), which are available on our site. 

Emissions Information

• This is a catback exhaust and does not alter, remove or replace any emissions equipment.

Specs & Features

• Material: Stainless Steel
  
• Includes: All hardware and gaskets
  
• Install: Bolt On
  
• Pipe Size: 70mm
  
• Tip Size: 110mm
• Two tip options are on this listing: polished stainless rolled tip (HS06HC2G3S) and titanium blue rolled tip (HS06HC2G3T). The piping and muffler are identical between both.
• The Q300 uses Invidia's Advantex muffler material internally, which optimizes backpressure for a deep refined tone without the volume or drone of a straight pipe or muffler delete.
• This is not a loud exhaust. Owners consistently describe it as noticeably better than stock but still completely livable on long highway drives. If you want something louder, Invidia's Q300 is probably not the one for you.
• The flat-bottom muffler design reduces aerodynamic drag at speed.
• 70mm mandrel-bent SUS304 stainless steel piping.
• Complete gaskets, hardware, and installation instructions are included.
• No tune required.
• Does not modify or remove any emissions equipment. 

The Q300 is the go-to exhaust for 8th gen Si Coupe owners who want a real upgrade without turning their daily driver into a noise complaint. The Advantex muffler material gives it a deep, full tone under acceleration while keeping it totally livable at highway speeds. No drone, no rasp, just a clean exhaust note.

This is the FG2 Coupe version. If you have an FA5 Sedan, you need a different SKU and we carry that separately.

70mm mandrel-bent SUS304 piping, 110mm rolled tip in polished or titanium blue. Everything you need to bolt it on is in the box. No tune required.

Pairs well with:

• aFe Takeda Stage-2 Cold Air Intake Honda Civic Si (2006-2011) Polished or Black Dyno-proven at 17 whp and 16 lb-ft on the K20Z3, the Takeda Stage-2 is the go-to intake for the 8th gen Si. Pair it with the Q300 and you've covered both ends of the engine on a street build without needing a tune.
• Silvers NEOMAX Coilovers Honda Civic Si FA5/FG2 (2006-2011) with Front Camber Plates A solid coilover option for the FG2 Si with 24-way damping and front camber plates included. Lower it, tune the damping, and add the Q300 for a clean all-around street build on the 8th gen.

Frequently Asked Questions

• Will this fit my Si Sedan?
  No. The Coupe and Sedan use different rear bumper exit configurations. This listing is FG2 Coupe only. The Si Sedan (FA5) needs HS06HC4G3S (polished) or HS06HC4G3T (titanium), which we carry separately. Make sure you know which body style you have before ordering.
• How loud is the Q300?
  Quiet for an aftermarket catback. Real owners consistently describe it as noticeably better than stock but completely fine on the highway with no drone. You hear it clearly when you get into the throttle, but it doesn't drone or rasp at cruise. If you want loud, this isn't it. The Q300 is for people who want a quality daily-driver tone, not maximum volume.
• What's the difference between polished and titanium blue tips?
  Same piping and muffler on both, just different tip finishes. The polished rolled tip is mirror-finish stainless. The titanium blue tip has a heat-treated burnt blue finish that deepens slightly over time with heat cycles. Purely cosmetic difference between the two SKUs.
• Do I need a tune after installing this?
  No. The Q300 is a bolt-on catback that doesn't touch the intake, sensors, or engine management. No tune needed at stock configuration.

OEM Part Numbers Cross Reference

• Honda Civic Si Coupe FG2 K20Z3 Rear Muffler Assembly: Honda 18030-SNX-A11
• This OEM part number applies to the rear muffler assembly on the 2006-2011 Civic Si Coupe with the K20Z3 engine.

The Invidia Q300 Exhaust is one of the most innovative exhaust systems on the market. The Q300 features a specially designed flat bottom muffler that ensures high speed aerodynamics often overlooked by other exhaust manufactures. The Invidia muffler has continuous piping so the exhaust has free flow through the muffler, reducing backpressure and increasing hrosepower and torque while producing the incredible sound that the Invidia Q300 exhaust is known for.

The Q300 utilizes SUS304 stainless steel that is one of the strongest on the market, and has a beautiful deep polish. All piping is mandrel bent for the best exhaust flow, and utilizes CNC machined flanges that are robot TIG welded to produce some of the best looking and strongest welds on the market. The Invidia Q300 is built to have outstanding durability and appearance.

Invidia Q300 Features

• Bolt on design - includes all necessary hardware for install
• Flat bottom design muffler for greater under body aerodynamics
• Free Flow Invidia Muffler
• Rich, Deep and Refined Sound
• SUS304 Polished Stainless Steel Mandrel Bent Piping
• Beautiful robot TIG welded exhaust flanges