Evening all. My S4 engined A6 has developed a high rev misfire on cylinder 5 and 6. It all seemed to start at the same time I ran the petrol tank lower than I have done before. If I take it up over 5k I get the mil light and very rough running. When I switch the engine off and re start all is fine. Since this started I have noticed a slight lack of power in very low revs compared to what I'm used to. So far I've swapped over the plugs and coils with no change. I've also fitted a new fuel filter and run a quarter tank of fuel with a bottle of Forte injector cleaner. Still no change. I've purchased a crank position sensor after reading other situations but not fitted it yet and if I'm honest I can't see it fixing the problem. A friend mentioned about a fuel tank pick up strainer being partially blocked. Does anyone know if the pump has this. I've also read that because it's 5 and 6 these are the last 2 cylinders on the fuel delivery strengthening the fuel starvation theory. I don't have VCDS but use the Torque app which has lots of which craft things on it that I've never used before. Any advice greatly appreciated before I spend vast amounts of money on the wrong parts. Thanks Brad.