Hi guys I need some advice please...
I have got a ford bmax 2013 1.4 petrol. Engine has got 42k on it

I've got my engine man light on.. code p0303 cylinder 3 misfire.

I've already replaced ignition coil, spark plugs, ht leads... engine management light came back on approx 1 week later.
I've had a diagnostics and compression test done ... all firing correctly no issues detected.

Changed the fuel injectors over (3&4) engine management light came back on later the same day... still same code.

I've been advised the next stage is testing the ECU and electrics (dont have a clue where or how to remove ECU)

Any other ideas or thoughts on this, the ECU idea sounds very expensive and I have got the Joy's of a MOT in the next couple of months so need to get to the bottom of this fast.

Any help is appreciated - thanks in advance