I live in Aus. and bought a '98 WRX 4 months ago. The car is virtually stock except for a catback pipe and a turbo timer and after market cruise control. Anyways, tonight I was driving and slowing down to the lights and it changed green so I started to accelerate again and the guy at the light (some Commodore) tried keeping up. My problem is that when I was accelerating from 3rd to 4th the car juttered/jerked, it did it twice then not again. I find it happens when I just plant it rather than build up my speed and so my dad said it might be that the car needs a tune up because too much fuel is being pumped through with the air. I'm not an expert when it comes to cars so any help or advice is appreciated!!