Checking brakes is simple. Raise wheel off ground and turn by hand. There will be some resistance since brake pads are contacting rotors, however w/o any pressure. Once I had a front brake caliper that would exert pressure but not relax the pressure when brake pedal was up. Brake drag was noticeable while driving and rotor got very hot. New rotor and caliper wre required. The problem was a sticking pistion in the caliper due to corrosion of piston (dust/cover boot was missing). If you can't turn the wheel by hand w/ only modest effort, something is wrong. I've never seen a load or torque spec for required rotation force, but would guess that 10-20 lb force on the tire outer surface should be sufficient to turn the wheel.

Another possibility for reduced gas mileage is a fuel leak. A small gas leak is difficult to detect and only clue is usually some gasoline smell.

Excess fuel pressure might cause increased consumption, and a fuel pressure check is not too difficult to perform.

Does car warm up quickly (w/i first 2-3 miles at street speeds)? If not, this could cause reduced fuel efficiency.

Also does coolant temperature indicator move to just below mid-range? Operating below design temp would also cause reduced fuel efficency.

good luck

 

I have a 2003 4-cylinder Honda Accord. First, regarding the gas light, I have also noticed that I only fill up around 13-13.5 gallons if I get gas soon after the light comes on. Rest assured there is plenty of gas left in the tank at the point the light comes on. I have driven over 100 miles with the light on without running out of gas (it's pretty scary as the indicator goes far below the empty line, but hey, I decided to trust the specs for the tank). Regarding your difference of a few mpg, I would have suggested that maybe you slightly changed your driving habits. I have noticed that going 55 mph with cruise control on I can get 47 mpg on the highway, but at 75 mph, I only get around 33 mpg. Winter makes a big difference in mpg as well. I always attributed it to the cost of warming up the engine, but maybe it has something to do with the winter fuel as some people have suggested. In the winter I only get around 15 mpg in the city, although most of the time I only drive a few miles at a time, and it seems mileage is worst in the first few miles after starting the engine. In the summer, I might get 20 mpg in the city.

I have had the check engine light come on recently and it seems the oxygen sensor needs replacing. I will see if my fuel efficiency improves after this change.

 

Don't assume the O2 sensor until you get the error code. There's hundreds of different things that MIGHT be causing the check-engine light.

 

The diagnostic codes that came up were for the O2 sensor and the infamous EVAP canister valve problem that seems to plague the 03 Accords. I noticed there is a recall for the latter issue. I am not the first owner of the car. Would I qualify for the recall even if the original owner had already serviced the car under the recall for the same problem?

 

OK I didn't realize you had the codes scanned. Sounded like you were just assuming...

Have you ruled out wiring problems for the O2 sensor?

Not sure about the recall, I think you'll have to ask a dealer.

If it had not been done already, then you would get the work done under the recall even though you aren't the first owner.

 

I noticed in another forum where a member continually tracks gas mileage, oil changes, etc., etc. He posted a plot of the data and what I found interesting was a notable shift in gas mileage starting in October and ending in April. From what I could tell, the drop was only about 1-2 mpg though and wouldn't explain the larger drop by itself.