Its probably simple but when I push the gas i get a whining sound coming from the front and back speakers. I have them hooked to an amp. The rca cables are no where near the power wire. Someone told me that its either the z2 is not grounded properly or the z2 is bad. Any help would be appreaicated.

Check the ground on your amp too

This is not usually a simple fix. You can get noise into your system through many places. Grounded RCA's, grounded speaker wires, bad ground, ground loops, bad head unit, bad amp, bad crossovers, bad alternator, non-suppression core ingnition wires, etc. I need to know more.

Don't forget about my favorite, loose or coroded battery terminals.

Or the old school, passive 12 dB/oct. crossovers zip-tied to a power line. That will give you slight noise, even if the amp is off. Fun.

what kind of car is it

I had this problem as well. My installer was very familiar with it and tried many different fixes (I have a 2006 camry). It is a known issue with pioneers and we ultimately had to remove the external amp and use the built in amp to get rid of the whining noise. As an alternative there are products that will convert your speaker outs to a line level out that will then allow you to use an external amp. You can avoid pioneers preamp out that way. But this has not been tested to the best of my knowledge.

Create a ground loop.

Take a wire and screw it onto the side of your z1. Take the other end of the wire and tape it to the metal on your RCA connector.

I had the same issue with mine and greating the ground loop listed above fixed me right up.