Rep Power: 0

Hi I have a 2004 civic with 65,000 miles on it. I've always gotten pretty good gas mileage as I drive around 120 miles a day for work. Just noticed within the last week that my gas mileage has dropped in half. Just need some advice on where to start looking for the problem. Do I need any sort of tune up? Thanks in advance for any help.

 
Rep Power: 249

air filter, tire pressure, o2 sensor. my guess is you have a bad o2 sensor.

 
Rep Power: 263

Take a look at the obvious....air filter & plugs really on that car. There is no ignition components, just plugs. Fuel filter is in the tank and I have never ever done a filter on our cars at my dealership. If you don't have a check engine light on then I would assume just the basics. If the check engine light is on go get it diagnosis'd

 
Rep Power: 812

either 02 sensor going bad, plugs, air filter, clogged injectors (use lubecontrol.com products). or low air pressure in tires, bad alignment, blown shocks, etc.

 
Rep Power: 0

i have the same problem 2000 honda civic ex, 67,000 mi. suppose to get 32 mpg but when i filled up and did the math about 23 mpg. whats up with that? filter did need to be changed though. what is an 02 sensor??

 
Rep Power: 239

check to see if ur gas cap is on right

 
Rep Power: 318

RedHonda00-

o2 sensor is an oxygen/air sensor in the exhaust (intake too, right? not sure...tired and all) that measures the gases to help make the engine run more efficiently

 
Rep Power: 0

What type of plugs you guys recommend?