Ok theres nothing you win but hey its fun!
Diagnostic says 1 and 6 are not firing. Car runs rough slightly. I think one of them is intermittently firing the other maybe not at all.
Possible causes according to diagnostic:
coil, plugs, injector, vacuum leak, wires (From memory)
Gas mileage is excellent. This makes me think its injectors. Failing plugs or wires would cause massive gas loss through misfiring cylinder.
Just bought this car. The seller said the wires and plugs are new. I will inspect tomorrow when I do the brakes.
Assuming they were replaced it leaves coil, vacuum or injectors.
Your thoughts? Much appreciated.