i bought the car with check engine light on and the diagnostic report said that the o2 sensor was bad...a full tank gets me about 300 miles....is that low due to the o2 sensor or is that not going to change much if i get it fixed?

thanks in advance.

 

i suggest searching some but it also helps to list the car

CD's don't seem to do too much better than 300-350 miles / gas light

drive like a granny
keep it below 80 and < 3k rpm
don't accelerate off the line like crazy
etc
etc

 

my bad. 97 accord EX 4dr 2.2l

 

replacing the O2 sensor will help; when the CEL is on the computer runs the car in 'default' mode.