No "Centrinos" (by which of course you meant Centrino badged system) are Pentium 4's! By definition it is impossible!
Perhaps what is confusing you (and some other people) is that there are Pentium 4-M's, which are Pentium 4's that were slightly modified for use in laptops. They don't compare at all to the Pentium M's though.
Centrinos have to meet three requirements. One of those is that it MUST have a "PENTIUM M PROCESSOR." If it doesn't have that or a Celeron M, then it is not a Centrino system.