Replace your restrictive OEM front pipe with a high flowing Invidia front pipe and gain hoursepower and torque for your Scion FR-S / Subaru BRZ.
Will this cause a Check Engine Light? (CEL)
This will not cause a CEL at all. The main CAT is located in the header, and the O2 sensor is also in the header after the CAT. There are no sensors after that therefore a catless front pipe will not cause any CEL issues at all.
This Invidia Catless front pipe contains no cat and is straight through 2.5" OD SUS304 Stainless Steel.