crappy mpg

[Spongebob 172]

what causes crappy mpg????
ive had a remap and use super unleaded,drive like miss daisy on most days but still i only get a 28-29mpg return why would this be..

 

[Peperami]

lambda sensor? If you have a decat fitted they go like theres no tomorrow.

 

[Spongebob 172]

not got it decatted...oh and hi peps