L322 Bmw 4.4 v8

Hi everyone I have recently brought a L322 v8 4.4 Bmw engine...... ok so guy I brought from said the spark plugs needed changing that’s why engine light was on me being from Gibraltar thought he’ll be honest as we are such a small place. I changed all spark plugs and one ignition coil as one seemed broken soo after reading up also found oil in the spark plugs and read here to Change valve cover gaskets so did that too now seems to be running worse tho seems to be burning oil and engine light still on any help would be great full planing on swapping all the ignition coils on Friday just to be safe but I there anything else I could do before I consider taking it to Land Rover and getting a massive bill ??

you could have a faulty plug, not clicked on the coils / lead properly?
Maybe check cylinder 8 plug/coil/lead?
Maybe swap coil over from another one and see if the fault moves, same with spark plug.
??
Best of luck

Hi all so you all know two coils weren’t working and changed valve cover gaskets! Should be picking her up tomorrow. Also has a o2 sensor fault if anyone knows where I can get best let me know thanks !