Hi. I am a newbie to the world of Subaru having only recently bought a 2004 plate 2.5 Sports Tourer. Within days of buying it the engine management light came on and I thought it might be helpful to share my experience. The car was also runing rough in lower gears and threatened to stall when slowing down at roundabouts etc. A very helpful auto electrican did the diagnostics and it was the front o2 sensor that was identified as the problem. A Denzo sensor was fitted but still the problem of the light and bad running continued. He recommended I take it to a Subaru dealer which I did. They identified the same problem and tried their own aftermarket sensor - no improvement. A Subaru own sensor was ordered and this time it did the trick - no more engine management light, no bad running - all running beautifully. I thought this might be useful to others who come across the same problem.
