Whats the best way to pin point a bad Catalytic converter, and bend ford's arm to fix it...i've checked and replaced all my 02 sensors (half the problem of my bad gas mileage), fuel filter, cleaned intakes, but i still get an egg smell and only ~250 miles to the tank with mixed driving. post away!
Silver 1998 Mystique LS (v6)...ATX

Removed Emblems, limo tint, painted calipers.
Premier P630 HU with 4 Pioneer TS-A6895 Speakers with 10' Sony sub (yeah i know, i'm cheap)
Commando 501-S Alarm