I have been having very bad mileage lately about 16-max 18 mpg with mixed city/highway using 93 and 87 octanes,
I have new plugs, autolites double platinum (changed from bosh platinum +2 with 3k but the same mileage), new fuel filter, recently cleaned EGR passages and TB,
could it be then because a plugged precat?, any other ideas for bad mileage?,
