Problem...
Engine has poor performance (limp home mode ??) centre cylinder seems not to be firing. Spark plug is sparking (though not as well as others) lead changed, no difference Engine can almost be discribed only running on four cylinders .
Tried to pull fault codes from A box but when I push the button the LED lights up straight away. No blinks ..the button is acting like a switch press it light on, let go light off.
Any thought would be apreciated.
John