Hi mate.
Oil quality is the oil type - i.e "2" is LongLife regime for petrol engine. "1" is fixed service all engines and "3" is longlife diesel. It is just a coding designation, not a measurement mate
Secondary air solenoid is the one that operates the 2 air control valves on the back of each cylinder head.
Lambda probe may be my fault!! I think I have put wrong side on!!!! I fitted to the pipe while it was out for the 'box!!! Sorry mate! My bad!!!
