04 tahoe weak heat in the front hot air but not a lot

[Bud Rozon]

It blows hot air in the front but it has recently lost pressure and does not blow nearly as strong now I put a new blower motor in it and it is still weak
Anybody else have this issue

 

[BatsTDK]

Evaporator clogged maybe? See link below. You'll have to cut a small opening into this box under the dash where there used to be a cabin air filter in the 2000-2002 models. Evaporator is right next to it. While you're doing it you could install the retrofit kit too.

https://www.tahoeyukonforum.com/threads/cabin-filter-retrofit.98974/