its not the cat, it has to be something to do with just cylinder 1, like a plug wire being routed the wrong way or a cracked head gasket on the outside of cyl 1, it could be alot of different things..im gonna say that you have a weak coil(ign coil), just because you said it only happends at high rpms and if the coil is weak then it cant fire enough voltage to over the high rpms..to test it i would take the coil for cyl 1, and swap it with a differnt coil, like taking the coil from the outside and moving it to the middle, if it is the coil then it should stop missing on cyl 1 and it should start to miss on whatever cyl you moved it to, and set another p030_ code for that cyl..
