Bad gas milage suddenly... What should I be checking?

["97z]

most likley causes for that are fuel pressure regulator or o2 sensors. pull the vacume line off the regulator and see if it leaks fuel out. second take your scanner and look at your long term and short term fuel trims they should be at zero +/- no more than 7 percent either way if so make shure o2 sensors are switching properly. hope this helps, adam