my car has died

i was driving today when the engine check light came on the car still drove ok apart from the fcd coming in at 4500rpm as usual when the lightis on. I drove about a mile then stopped the engine i tried to restart it about 5 minutes later and it struggled to start, when it eventually did it kept cutting out.

with revs held on i can keep the engine running but only just its missing and back firing all over the place.

the engine check lamp is not on now ive tried to read the codes but it just gives a constant 0.5 of a second flash indicating there is no faults.

it feels like fuel starvation but ive had the pipe from the filter of and there is plenty of fuel there and seems to have a decent pressure.

when the engine is running and the throttle is pressed there is a loud clicking/ cracking noise coming from the throttle body area

any advice or helpfull hints welcome

by the way its a 97 sti

 

sounds like a vacum pipe may have come off or split/ dump valve return pipe even?

 

air leak was one thought i had. i had a look around couldnt see anything obvious but ill start pulling things to bits tomorrow for a better look