I have a 1999 chevy tahoe 4x4 when i drive it it chokes like it was going to turn off i took it to a mechanic and he said it was fuel pump i checked and i can hear the fuel pump is working i think it could be the fuiel pump filter what do you think it could be

No. 1-1

of course change the filter FIRST,cause a clogged on would do that. THEN, if it doesn't run right, pressure test the fuel pump to see if it's bad. Clogged filters give low pressure readings all the time.