hi i know this sort of thread has been up many times before sorry. my problem is that my a3 is misfiring from 2000 -3000 revs and only under load ive checked all the obvious replaced spark plugs 2 coil packs and the ignition module and checked the air flow meter and injectors so i took it to an auto electrician and they ran a diagnostic and it said inttermittent fault on injector 1 so i swapped number 1 with number 4 to see if it would blacken up the spark plug like it was doing an then to no avail its now not making any of the spark plugs blacken ive ruled most things out im taking it for a compression test tommorrow but other than that i really dont know what to do. any help would be really appreciated thanks