99 Nissan Maxima SE, 5spd manual, 56000 miles. My Maxima is really hesitating and sputtering as I accelerate from a stop. It runs fine after 3rd gear. But getting from first through third the acceleration is weak. The idle is pretty good but there is a slight and sporadic sputter when stopped. Currently the 'check engine light' is on. Within the last year I have had 2 oxygen sensors replaced. Could it be something else? How many o2 sensors are there? Fuel filter? MAF sensor? What can I try on my own before I go back to a mechanic?