I have a stock obd0 b16A in a 95 civic ex. I bought the car like that and for some reason ever since I bought it I have horrible gas mileage. I get like 10-12 miles per gallon. On a full tank I only drive about 120 miles. The most I ever got was 160. What can be wrong with car? Is it ECU? O2 sensors? The car runs fine. And no signs or symptoms of the car running rich such as black smoke or gas odor. Help

 

check air filter and ignition

 

I have new spectre air filter...sparks plugs and wires new. The only other igniyion part I can think about is o2 sensors

 

Wear gloves and pull a plug. Hold the plug with pliers that have an insulated grip, connect the plug to a wire and touch the plug threads to the valve cover. Have an assistant crank the motor a few times while you carefully watch the spark. It should be a bright pink/blue. Do this with all 4 wires. When done with a new plug, this will show most problems with the ignition system- coil, cap, rotor, wires and grounds. An O2 sensor problem will usually throw a code. Check ignition timing and MAP sensor voltage at idle and as the throttle is opened.

 

Do a big tune up. One thing that could be draining your gas mileage could be broken wheel bearings. Check them. is a bitch to check them but if thats the case then thats giving your car major drag because your car is being forced because of the broken bearings or worn bearings.

 

Change the distributor cap/rotor, spark plugs/wires. Oil change etc.