Not a direct fit--the DE5 exhaust is ~5in longer, so it'll require a cut and weld.
Do keep in mind the DE5's exhaust is very similar, it's just missing a resonator and the car is tuned a little differently for pops and bangs.
You can likely keep your FL5 exhaust, remove a resonator, and have Hondata tune the car for the same/better effect at a cheaper price than sourcing a DE5 exhaust + modification + install.