If you are looking for the high flow cat and still need emission control and don't want to sacrifice the flow and performance, then look no further. Handbuilt, TIG welded 3" cat with 200 CPSI is simple and efficient design that provides all the flow you will ever need for your 4C pushing up to 450 HP without worrying of exhaust system being the bottle neck. Drastic temperature drop in the exhaust system in the turbo and least possible backpressure. Engine stability on the track is immensely improved. Engine bay temp is reduced and engine response is increased. This cat is N/CE, Euro4 rated and legal in most countries, but please check your laws and requirements for street driving your car.
 
This GMS 3" 200 cell or 400 cell high flow catalytic converter is a part of fully modular GMS 3'' exhaust system and can be combined with all the other GMS exhaust parts you need.
 
GMS 3" 200 cell high flow catalytic converter, features larger holes with a less dense matrix, allowing for superior exhaust flow, more horsepower, and a louder, aggressive exhaust note. These are highly favored for track builds and modified street cars.
 
GMS 3" 400 cell high flow catalytic converter,  features a denser matrix, prioritizing maximum emissions filtering and odor reduction over peak performance. It is quieter and is the safer bet to avoid a Check Engine Light (CEL)and potential tehcnical insepction fails.
 
Dyno proven, 5hp - 7hp power increase over stock exhaust system on stock 4C.
Dyno proven, 11hp - 17hp power increase over stock exhaust system on ECU tuned 4C.
 
Next step is GMS 3" Midpipe.