I have a '99 V6 that I purchased a few months ago. I never really cared much about the fuel economy of it or worried about it, but I'm putting in about $20 (7 gallons) to get myself UP TO like 80-100 miles, when in reality I should be getting closer to 160 or 180. I'm gonna be replacing the spark plugs with NGK G-Power, but I wanna note I don't have my cats on my car, it stops about halfway under the car at the...Y-Pipe? I don't believe the exhaust is causing an issue with the MPG, but if you guys think so, that would be nice. I plan to buy a dual exhaust converter kit when I get the money so I can pass inspection in December. Any ideas what else it could be?