Flashing Engine Management light only on over run
I wonder if anyone can help with a small problem I am having with my 156.
About once or twice a week on the motorway if I back off the gas when at 70MPH the engine management light starts to flash. If I keep off the gas it keeps flashing until I get down to about 65 mph, but if I put my foot down it stops immediately. If I then back off it starts to flash again. The weird thing this is not repeatable, so when I go down the next hill the light stays off
Every so often the light stays on permanently Fiat Scan gives the reported failure as P0300, random miss fire.
The car pulls fine and I am getting about 30mpg. I have checked the plug and they have a light grey covering and I have also looked for air leaks on the inlet but have not found anything.
Does anyone else have any thoughts on what this could be?