why do my 03 sedan feel like it has more low end torque than my 05 coupe,or is it just me.

it could be due to the fact that the sedan has a a little more weight on the rear tires, that it seems a little more "planted"

It may actually have a bit more low-end. Hard to say for sure without dynos, but based on the torque and HP ratings, the sedan may have a broader torque curve at RPM's lower than the torque peak. The Sedan has a faster drop off after the torque peak than the coupe which may be because the cams are optimized for more torque at lower RPM's. All coupe motors(including the rev-up version) are optimized to have a bit more top-end. On the non-rev-up, this is apparent in that they did so by boosting the torque by 10 lb-ft. and they managed to keep torque levels higher through to at least the HP peak. Based on these factors and the nature of how engine breathing characteristics affect the torque/HP peak relationship, that's my speculation.

I noticed the loaner sedans I drove did feel peppier at lower RPM's.

your right about the low-end drop off in the sedan compare to the coupe,cause the coupe feels way faster at top-end speed,so i guess it wasn't me.