There are 100% definitely performance gains to going with a high-flow cat or full cat bypass. The ECU will recognize higher flow and make a minor adjustment. This adjustment is not substantial enough to keep up with the amount of extra flow that a high-flow cat or catbypass. More airflow = more power.
I have had my Sport Cat on my car for almost a year now and it still pulls just as hard and definitely harder than stock. Check out our dyno graphs below of the power we made with our Sport Cat Downpipe.
