RPM power range for a 90hp 2002 jetta tdi no mods

I just bought a 2002 jetta tdi ALH 1.9 90hp. My car makes good power up to approx 4200 rpm then falls off big time. Is this normal for this engine? I have read threads that say their car runs strong to redline. I took off the snow screen for summer and have a new air filter. The car has 80k on it. I have not checked the intake track yet but was wondering if the car is working normally before I start digging. My VW dealership just replaced the Air mass meter with a new one about 1k miles ago.
Thanks
2002tdijetta

Perfectly normal.

Thanks Meister