Is it the subs or amp??

You could also be referring to a common problem found in the sony 2-channel amps.  I've have the 1002hx? and 2165sx, and over the years I've come to find out that these amps are notorious for going into protection when bridging them to run subs.  They're fine for running anything in 2-channel like midrange, but for some reason they can't handle the demands of a single bridged sub.  I haven't used anything sony since the sx a few years ago, but unless they've rectified the problem you could be SOL.

P.S.  You can expect a channel (the right, I think) to completely fry within three years if you continue to drive it into protection.  It happened on both of my amps.  One was out of warranty and the other had a three year so it was replaced.  To this day it only runs my 6x9's without any problems.

You could also be referring to a common problem found in the sony 2-channel amps.  I've have the 1002hx? and 2150sx?(2001), and over the years I've come to find out that these amps are notorious for going into protection when bridging them to run subs.  They're fine for running anything in 2-channel like midrange, but for some reason they can't handle the demands of a single bridged sub.  I haven't used anything sony since the sx a few years ago, but unless they've rectified the problem you could be SOL.

P.S.  You can expect a channel (the right, I think) to completely fry within three years if you continue to drive it into protection.  It happened on both of my amps.  One was out of warranty and the other had a three year so it was replaced.  To this day it only runs my 6x9's without any problems.