Is it possible that my 2000 Honda Civic si could be an EJ8?

Everywhere that I have read says that the si is an EM1 but the chassis code on my car says EJ8.

All 1999-2000 Civic SI Coupe has chassis code EM1:
Chassis Code: EM1
Engine Code: B16A2
Engine Type: 1.6L 16-valve DOHC VTEC I4
Horsepower: 160 hp @ 7600 rpm
Torque: 111 lb-ft @ 7000 rpm
Compression Ratio: 10.2:1
Transmissions: 5MT
Weight: 2612 (99), 2601 (00)

Note: Besides your SI couple: The chassis code EJ is a bit more confusing since it covers both fifth and sixth generations of Civics in the US alone. Nearly all US 6th gen Civics are EJs though, while all US 5th gen coupes are EJs. The only 6th gen Civics in the US that are not EJ chassis are the EM1 and EN1.

These are the Civic that has code EJ8:
1996-2000 Civic EX Coupe
1996-2000 Civic EX Sedan.

Could just be that any previous owner did an si convertion which is basically replacing everything from the original Ej8 civic with the si mods (motor, front end, interior, etc.) .