over last couple of days the emissions light has been coming on in my mk4 gsi. 1st gear seems alright soon as put it in 2nd and put foot down a bit it like judders (hard to explain)and makes sort of like a loud gargling sound as im accelerating, with loss of power. then emissions light comes on (flashing) then stays constant. if i stop the car and leave it ticking over wihle im stationary it wobbles a hell of a lot more than it should do, i.e you can feel the engine shakin sat in the car, almost like its misfiring or sumat??. also when turn engine off then back on again the problem goes instantly. but set off and put your foot down again then same thing happens.
exhaust seems alright and solid externally i.e its not loose or out anywhere that i can see. its got the full milltek set up and high flow precat on it.