i highly reccommend you change your O2 sensor. I have been replacing sensors cleaning crap all over my car , but to no avail to better gas mileage ( about 21 mpg on the hwy ) . I finally dropped the cash for the sensor from www.oxygensensors.com and go tthe removal socket for 51 bux shipped to my door. Now I'm at 50 miles and barely moved off the full line. Usually it would be already down a 1/4 of a tank. I'm soooooo happy , It also runs alot smoother now. No hesitation when barely pressing on the gas. Overall I highly reccommend it. But getting the old one off I got