I swapped a Vibrant #1791 resonator in place of the OEM bottle! The cold start is much louder than before. I'm really happy with the increase in exhaust flow underneath the car. Next step would be a second cat delete.
2015 Mazda 6, Skyactiv 2.5 Cold Start W/ Light Revs (Vibrant Resonator in place of OEM)
the stock resonator has been replaced with a vibrant 1791 bottle style resonator. 91 Octane. cold start at -5C weather.
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