Greddy Supreme SP causing CEL?

[Clipdat]

That's sound logical, until you realize that Subaru has been known to decline warranty coverage for any and all reasons, tuned or not.

Might as well just tune it because if something happens they're just as likely to not cover it even with the stock tune. So my thought is; tune it now and get the most enjoyment out of it that's physically possible. Life is short.

[SydBRZ]

Originally Posted by AlexBRZ2

I don’t have check engine light. My car is running perfectly. I just want to make sure I won’t need to tune my care if I decide to add the catback exhaust.

The check engine light that I brought up was because someone who posted a YouTube video had a CEL with the same header, catback that I want, but a Motiv catted front pipe. I plan to keep the stock front pipe.

If you were going to throw a CEL, it would have happened when you changed to aftermarket headers. This is because the O2 sensors monitoring the primary cats in the headers would start reading values differing from stock. A tune (OFT or otherwise) will disable these codes.

Having an OFT means you can flash the car back to the stock tune before visiting a dealership. They'll still be able to see your aftermarket exhaust tho!
To my mind there is no point in changing exhaust headers and other hardware unless you plan to tune - especially considering you can flash back to stock with your OFT at any time.

TLDR:
Changing the catback alone won't cause you to throw a CEL.
Get an OFT and tune - you can easily flash back to stock.