just baught this s13 with 160,000 on it ran fine during test drive after i got it it it stated to hesitate under medium and hard throtle. started to get worse now it runs but barley while driving anything over quarter throttle it dose not accelerate. if u try to give it gas feels like it tryes to go but then dosent. i think it may be my air flow meter. any sudgestions on how to eliminate or confrm the air flow meter. or any other sudgestions on the cause of this.