ScienceofSpeed Factory-Replacement Catalytic Converter Set - NSX, 1991-05


Direct-replacement catalytic converters for the three exhaust year generations, 1991-94, 1995-99, and 2000-05 using high-quality EPA approved catalytic converters. This catalytic converter is not CARB approved for use in California.

Designed & manufactured by ScienceofSpeed - these catalytic converters feature T304 stainless steel, TIG welded tubing, converter bodies, and rod. High flow catalytic converter cores are rated for over 375 BHP. 1991-94 includes required hardware & crush seals. 1995-2005 compatible with existing factory hardware & gaskets.

Should not be used in applications where the engine air/fuel mixture is excessively rich (<11.5:1 AFR) such as with Comptech / CT-Engineering Superchargers. For these applications and high-performance supercharged or turbocharged applications, please consider the ScienceofSpeed High Output Catalytic Converter Set for Forced Induction.


  • Direct-replacement for factory catalytic converters.
  • Mounts to exhaust manifolds, headers, and exhaust mufflers with flanges in the factory locations.
  • Designed to flow up to 44 LBS/MIN of air mass (375 BHP). 
  • 304 stainless steel tubing.
  • Precision back-purged TIG welding.
  • Manufactured by ScienceofSpeed in the USA.


  • Front & rear cylinder bank catalytic converter set.
  • Output flange crush seals (1991-94).
  • Mounting fasteners (1991-94).
ScienceofSpeed Factory-Replacement Catalytic Converter Set - NSX, 1991-05



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