Rear lambda sensor
 

Put the car upto a diagnostic computer and it came up with 02 rear "lambda" took it out and the plug was rattling is that ment to happen ? Also would the lambda cause petrol to come out of exhaust run lumpy at idle and smell very rich? Cheers

It will run rich yes,but define petrol coming from the exhaust as fumes are meant too lol?

Spitting out petrol little splashes

That will be water.

If it was petrol, the flames from natural combustion would have ignited it long before it got to the exhaust tip. (like within a few inches of going into the exhaust mani)

And would the faulty lambda sensor cause this ? Cheers mate

Potentially yes, the lamdba can cause rough idling and rich fuel mixture.