hi im new to this have just bought a p38 couple of bits need doing to it,i have 20" wheels on it but has different ssize tyres on rear any idea what correct size should be? also have been told it needs a new abs sensor how much am i looking and can i fit it myself? thank you

as long as all 4 match on size eg 225 45 20 all the way round that will be ok if they are odd sizes you stand a chance of doing the gearbox/transfer box or a diff in