I have both units and for some reason sound is super low and has lots of noise, do I need to hook the EQ to the front amp preout instead of rear?

I had it in the rear for last head unit no problem. Book for eq says use rear, but pioneer online support says use front.

WTH?

ha u kno i had the same prob,could not figure it out i put a ground wire on the rca and it stop most of it but still try n to figure it out but its a lot better