Hi people, my 94 uk Impreza runs rough as anything on idle but drives spot on, if I am stationary and hold the revs slightly it pops and bangs. Any ideas as 2 where I should go 1st?

 

Air/vac pipes,lambda sensor,one of the coil packs(guessing it has singles being early car) have you got any fault codes showing?

 

Can't see any pipes split or off anywhere. I do have a leak on 1 of the rocket gaskets so could be getting to 1 of the coils perhaps? Not done a code read yet, will do Monday when I get back to work as the cars parked there for now

 

No fault codes showing at all, check engine light just flashes continuously which I think means everything ok? Any more suggestions or shall I just go ahead and replace rocker gaskets and plugs and see how it runs?