Is it possible to put an aftermarket sub in truck but have it wired to the factory amp so I have sub control and maybe a little better sounding bass?

 

You will never be happy with the sub output using the factory amp. You can add an amp and sub and still retain sub control from the HU.

 

^ What pohljm said. I believe there is only 40w going to the stock sub, so that wouldn't really do much for an aftermarket sub.

 

Is there a how to? i havent found it.

 

^^^How to what?

What the others have said, however you can use the signal wires before or after the amp and route them to an aftermarket amp via a Line Driver or Line Out Converter, which will still give you control of the sub volume via the head unit.

 

https://acurazine.com/forums/3g-tl-audio-bluetooth-electronics-navigation-94/diy-aftermarket-amp-install-speaker-install-audiocontrol-matrix-install-w-pics-580314/

 

wiring subs and amp with stock headunit is really simple, everyone uses line out converters