sputters and acts like it going to stall

My 2000 Toyota echo has acceleration problems at low speeds& when first started. could it be the fuel filter? if so is there an in line fuel filter as well as the in tank filter?it sputters and acts like it going to stall. but, if i let up on the gas a second it will start to run okay. once it is warmed up or up to about 35 mph it is okay.