Invidia HS12HC4G3S Q300 Cat-Back Exhaust System for 12-15 Honda Civic Si Sedan

Vehicle Fitment

• 2012-2015 Honda Civic Si Sedan (4-door)

Fitment Notes

• Cat-back exhaust system - replaces from catalytic converter to tips
• Not compatible with coupe or hatchback body styles
• Includes all necessary gaskets and hardware for direct bolt-on

Features

• Mandrel-bent 70 mm (2.75") piping (SUS304 stainless steel)
• Flat-bottom muffler for improved high-speed aerodynamics
• Robot TIG-welded with CNC-machined flanges
• Rolled 110 mm stainless steel tips (double-wall)
• Advantex muffler liner with continuous piping for free-flow and optimized back pressure
• Delivers increased horsepower, torque, throttle response, and a rich sporty tone

Specifications

• Piping: 70 mm
• Tip Outer Diameter: 110 mm
• Material: SUS304 stainless steel
• Construction: Mandrel-bent, CNC flanges, TIG welds
• Includes: Mounting hardware and gaskets

Included Components

• 1x Q300 cat-back exhaust assembly
• 2x Stainless rolled tips
• Hardware & gaskets

Product Description

The Invidia HS12HC4G3S Q300 Cat-Back Exhaust is designed specifically for 2012-2015 Honda Civic Si Sedan models. Crafted from SUS304 stainless steel with mandrel-bent 70 mm piping and a flat-bottom muffler, this system improves exhaust flow via continuous piping and Advantex lining. The result is smoother high-speed aerodynamics, increased horsepower, torque, and sharper throttle response without compromising sound quality. Finished with rolled 110 mm stainless tips, CNC flanges, and TIG welds, it offers both performance and reliability with OEM-style fitment.