First of all, You need 1337 stats.
Here it is:

#1337 Stats
;Credit SonniE
0x00b4e9ec 0x0539
0x00b4e9ee 0x0539
0x00b4e9f0 0x0539
0x00b4e9f2 0x0539
0x00b4e9f4 0x0539
0x00b4e9f6 0x0539
0x00b4e9f8 0x0539
0x00b4e9fa 0x0539

1.)Go in a room and enable the code.
After you done that highlite the cheat
and press triangle. Scroll to
"Value.dec" and there it should say "eight 1337's"
Well, the first four are games
won, and the last four are games played.
Edit those numbers to what you want your
stats to be, now disable then enable the
code.

2.)After you done that, play a ranked
game and finish it. After you reach the
lobby press home to quit and select
"yes." to go to your XMB.

3.) Now completely shut off your psp,
and turn it back on holding the "R"
button and exit recovery mode.

4.)Load syphon filter, and log in, and you
should start with the stats that you
modified.

Enjoy!!


Credit To SonniE for 1337 stats