KA24e low gas mileage

[chriskapinos]

I have a ka24e in my 88 s12, i use an automatic ecu, because i was told there was issues with the speed sensor using a manual ecu. i seem to be getting only 17 - 20 mpg, not beating on the car engine is stock to my knowledge with only injen cai. any suggestions as to why my gas mileage is so low?

[gtc_240sx]

try replacing oxygen sensor

[chriskapinos]

meh new like 12k ago

[-RJ-]

use synthetic oil

[gumby74]

Tune-up to include filters, check ignition timing, check and clean corrosion off connectors, clean maf.I was averaging 20-21 mpg before doing this. Now I am at just over 25mpg, also on a KA E.