2AWG is rated at up to 180A continuous and your amp certainly won't draw that kind of current on a continuous basis. However, at low voltages like the 12V in car power systems, voltage drop across a length of cable is of concern. I think if you were to replace that 2AWG with 0AWG cable, you won't run into any problems in future. The best way would be to put a distribution block close to your amps and run the 0AWG to that, then run 2AWG from tehre to the amps. It's best to run the earth of the amps to a common earthing point, too. Make sure you upgrade the earth wire at the same time as your power cable.