hi , ive got a 2001 impreza gx non turbo and i have started getting around 150 mile on a full tank while driving steady, it used to do about 250.
there is no smell of fuel so i dont think it is leaking.
the only thing i have noticed recently is rarely it is hesitant at low revs.
any ideas anyone what could be wrong ?
im thinking the maf may be faulty.
had a friend scan for faults but non were found.

 

I have before same problem and this problem has been with O2 sensor,after replacing O2 sensor we are manage 330miles on full tank,this has been unthinkable with O2 fault(with faulty O2 we are manage 160-180miles)