Code P0430 - Aftermarket Exhaust

btfrost20

Hey guys, first time posting here. I just had my "Service Engine Soon" light come on after buying my 2014 370z 3 months ago. There are about 15k miles on the car, and the previous owner had a custom exhaust installed, as well as dual air intakes(as far as I can tell; Nissan dealership didn't include details on what modifications he made).

I took the car to a nearby AutoZone and they told me that it was a Code P0430 and that I should just use premium gas with an octane boost(I already use premium) and to check the air intakes for any problems.

The sound coming from the air intakes is much more audible now, and it seems to be noisier at 4k rpms(I haven't gone much higher since the engine light turned on, don't want to screw anything up). Is the AutoZone employee's advice correct or could it be a lot worse, like having to replace O2 sensors/the entire cat? Thanks for any help.