ive done a bit of searching around for similar problems, and it seems to all go to the egr valve dooby gunking up etc.
My car started really rough 2 days ago, terrible idle, between 500-1000 rpm sort of bounce and sounding like a misfire, car shuddering. so i turned it off. started 2 seconds later, normal. so i think yeh hey whatever.
next day no dice, even worse almost stalls, so i reved the guts out of it till it warmed up and then..fine, idle's fine. But i notice at low speeds say 20-30ks in 2 second gear around round abouts i get a sort of hiss sound and the engine basically drives like 50 of its horses just got shot, till i straighten up the wheel and accelerate back up to speed.
Only occurs at low speed and turning or when under strain, ie uphill in a higher gear when the revs are low.
Does this sound like a dirty throttle body, egr, plugs, AFM ?? i have been running an aftermarket air filter k&n i practically just clean it like instructed and use no oil, cause it destroys the afm right?