Car Boggs down at 2000 rpm

I accidentally drove my car with the air filter box open and since then it won't
run past 2000rpm , when I try to give it gas it Boggs down and starts running
real rough and sounds like it's loading up and sometimes will stall . It idles
fine it didn't have any symptoms of any kind and ran perfect until I drove it
with the air on open . I changed the map sensor and the mass airflow sensor
and it did not help