The catylist system issue is the o2 sensors. The downstream one is telling you there is an issue with exhaust.....I would replace both upstream o2 sensors....
That could be causing the lean mixture issue as well as the mas sensor.
Once you change those parts run it a bit then check for codes again to see if the misfire and lean issues go away.

 

Misfire has gone after cleaning the MAF and i ran it straight after, went up the road and the CES light came on again showing multiple misfire, cleared that did a 5 mile run on petrol and LPG and the light never came back on.

Will give it a proper drive over the weekend.

Thanks again