air mass sensor or ERG gone

[joe86]

I have had my 2006 ford focus code read and it told me that the air mass sensor needed replacing, I have done this and my car is still the same and will not start again after being ran, I have also changed the EGR as was told that this could also cause the car from not starting.

Can anyone shed any light on why the car will not start again after being driven?

Thanks in advance.

Joe