Ive got my hands on a 2016 gibson SG standard, with p90's equipped from the factory.

I decided to switch them out for EMG's because I'm primarily a metal player, so I got the P81/P60 EMG and installed them as to avoid routing the guitar.

I installed them and they appear to be working, but the output is very bad, on my 6505 I'm getting only a clean sound even through my Red channel, on my buddies EVH 5150 4x12, same story. 

The only thing that I needed to solder in the kit was the cheap switch I installed in place of the quality gibson one, I needed to change it for one with more room as to avoid routing the harness box. Obviously I'm a bit frustrated as I did everything the correct more expensive way to avoid hurting the guitar in the changeover.

Before anyone asks, yes, a new battery was the first thing I tried. Now on P90 stock pickups, there is a steel metal plate that the p90 mounts too underneath the case, I modified those slightly to work with my EMG's, but I started to theorize that maybe, since EMG magnets are weaker then passive, could that be interfering and cutting out my drive signal?

Any ideas? I'd really appreciate the help as I really just wanna play my sg again.  

are you still using the mono output jack?  if so, you will need to change it to a stereo jack.