I have the same Coupe (2001, I4, EX, 6-Disc/6-Speakers). There isn't an amp.

Did you use an Stock-Aftermarket Adapter Harness or cut up the wires on your own?

It is most likely a grounding issue. Try grounding your wire to that bolt in the center frame. If you are sure to have a decent grounding place, then I would check your Adapter to make sure that no wire is pulled out/loose. If you cut the wires, then check all the wiring again.

But, I'm pretty sure that the 01 Coupe EX doesnt come with a factory amp.

Let me know how it goes.