Hi all - I have an '04 Discovery with ~95,000 miles. Head gasket, cats, and O2s all replaced this summer. It was running well until about 3 miles into a drive last weekend when the engine suddenly was running rougher with loss of power and a sometimes steady, sometimes flashing SES light. Codes are: P0300, P0302, P0462, P1300, P0303. Any suggestions on where to start? Plugs and wires? Coils? Somewhere else?