Is there an ecu adjustment that can effect or restore previous mpg? My mileage is way off even though all my sensors are relatively new.

 

Lower mileage has alot of factors that can contribute to it. Bad spark plugs, vacuum leaks, dirty throttle body, low tires pressure, added weight to the vehicle, dirty air filter, improper octane/cheap gas, all this will not trip a CEL. Knock sensor will not trip a CEL but when you do the diagnostic it will show, if the ks is bad you lose mpg.

 

make sure your tires are in good condition for better gas mileage... and that you aren't on the gas too much

 

A clogged EGR tubing may be contributing too...Have you clean it?

 

What is your actual MPG?
How did you calculate it?
What are your driving habits, mostly city, highway or a combo of the two?