alright so i have posted this before... I have a 95 civic eg coupe with a obd0 b16a. It has brand new ignition parts but still seems to get poor gas mileage... i grandma drive the car and still only get about 10-20 mpg... its weird cuz sometimes a full tank will give me 140 miles and someitmes up to 240...... the only mods i have is an aem intake....and the car came with a huge exhaust.... looks like 3 inch piping all the way back....i dont smell my car burning to much fuel...no gas smell.... no black smoke.. so can exhaust be problem? what bout oxy sensors? help please