Sunfire GT 98 2.4L jerking, need help !

Alright, here's the problem
I recently had an accident, guy cuts me at the last minutes, it was on snow, no choice to go straight into his car !

A new problem came up since then !, car started to jerk, as if it was missing gaz, but it's not !, does this rarely, like 2or 3 times in 2 days and always when i'm on 3rd,4th or 5th gear reving at about 1500rpm, car should normally force while it starts to rev up more ! that's when the jerk part comes in, the car forces to go forward and the car will jerk 1 or 2 times in a row then it is okay !

now, fuel filter has been changer, air filter seems to be clean ! only thing remaining, sparks plugs ? (the car now has 160 000km on it) sparks plugs wires which doesn't seem to exist on these motor ?

I removed the head, (thing with 2.4L twin cam written on it !), i see the spark plugs, and a kind of weird thing "T" shaped that goes into the plugs and there seems to an electrical module too ? what's the purpose of that thing ? what if it's defective, could this be what's causing my problem ?

sorry for the essay, just needed to clarify a few things
Thanks :p

I know it's cavalier forum, but since it's the same thing as a Z24.. why not ask it here too ! :)

The "head" you were referring to is actually the ignition cover, the module on the underside is the coil pack, they connect directly to the spark plugs, that is why there are no spark plug wires. I'd check the vacuum lines, especially the one leading to the MAP sensor (mounted on the frontside of the throttle body), the vac line on my MAP sensor was split and it caused some hesitation and bucking. hope this helps!