Hi car is subaru impreza wrx 2 litre turbo 1993 japanese import 76000 miles ,my results were,co 3.17% failed, hc 173,pass, lamb 0.92 failed, have been told the cat is no good ,it passes on idle speed but fails when revving ,any ideas would be greatful, i took car for mot warmed up for 10 minutes on tick over is the cat hot enough or do i need to take it for a thrashing first many thanks ,shawn