I got my FPR replaced and the gas milage went from about 6mpg, to about 12mpg. Could my 02 sensors have been damaged when the FPR was broken? What else could be causing the milage? The explorer has 165,000 miles. Its mostly city driving, but some highway. Help! thanks

Change the O2 and clean the Mass Air Sensor..Should help..Can't hurt..

Ok, where exactly is the 02 sensor, I know its somewhere near a cat. I just cleaned the mas, about 2k miles ago.

They're located in the exhaust pipes (one in each) just before they come together at the y-pipe. The connectors are a mother to get at...