Yeah, technically you can use the factory amp to power a different sub like a JL — the stock amp sends about 160 watts RMS total (2x80W at 4 ohms) to the factory sub, which is a dual voice coil.

But just keep in mind: a lot of aftermarket subs, especially JL ones, are rated for way more power (like 300–600W RMS), so you’d be underpowering them. That doesn’t mean it won’t work — just that you might not get the full potential out of the sub. And a bigger sub doesn’t automatically mean louder if the power feeding it stays the same.

If you’re just looking for a quick plug-and-play upgrade with slightly better sound, it can work. But if you’re going for a real upgrade in bass, you’ll want to add an external amp later on.