Hi,
I've had my 97 LX for about 6 years. It has about 120,000 miles. I've always been in the habit of checking my mileage after every fill-up.

My question in brief
The problem I'm posting about is that my mileage always averaged 22.5 overall until it suddenly dropped to averaging 18 mpg around June. I have had 2 Honda dealers and a Honda specialist look at but apparently they rely solely on codes to diagnose problems and the only code I've had seems to be unrelated (so I'm told).

Recently, I realized that since my mpg has been bad, my "low fuel" light doesn't come on as soon as did before. The last time it came on I figure I had less than a gallon of gas left in my tank (it used to come on with 2 or 3 gallons left - back when all was well). It took me a while to realize and figure this because I don't normally run it so low. But I had noticed previously that the needle looked awfully low for the fuel light to not be on yet.

So I'm wondering (since the Honda mechanics are no help) if it's a clue to my mpg problem that fuel light takes longer to come on than it used to.

The details
In case it matters, here is what happened leading up to when, and since, the mpg trouble started:

1) The Check Engine light came on.
2) After a week or two I took it to Advance Auto. They read the code (I've forgotten the code number now) and turned off the Check Engine light at my request so I could see if would come back on.
3) About a week later it came back on, so I took it back to Advance and they read the same code and turned off the light again.
4) It came back on again a week or so later, and after a couple of weeks I took it to Honda dealer#1 for repair.
5) Honda dealer#1 said I needed a purge control solenoid valve (which was what the guys at Advance Auto had speculated) and also a canister, which would cost $700.
6) Shocked at the cost, and having read that I wouldn't hurt my CRV if I didn't do the repair immediately, I declined the repair and picked it up. (They turned off the CE light)
7) Starting with the very next fill-up, my mileage went from 22.5 mpg average to 18, and has been there ever since. (It had not changed at all until the dealer had it. The CE light had never affected it.)
8) This time the CE light took 5 weeks to come back on. When it finally did, for a second opinion, and because of what had happened with my mpg, I took the CRV to Honda dealer#2.
9) I showed them the CE light and told them about the bad gas mileage that was happening. They diagnosed the fix for the CE light as being the same problem as dealer#1, but said the repair and a tune up would be covered for free under Honda's "good will" program, so it all cost me $zero. However, they couldn't find an explanation for the drop in mpg.
10) So the cause of my CE light was fixed, but the bad gas mileage continued.
11) I looked on the internet and found that a bad front o2 sensor could cause bad gas mileage, so I replaced it (myself) with a Bosch Direct OEM replacement model (ie, not a genuine Honda). No change.

So...
Does anyone know if the drop in mpg could be related to the fuel light taking longer before it comes on than it did when I had normal (good) gas mileage?

Or what could be causing it?!

Thanks for your help.

 

The fuel light can only be the fuel sending unit. (mine does pretty much the same ting)
The bad gas mileage is at least partially due to the Bosch O2 sensor, but more likely the switch from summer to winter fuel.

 

I normally get about 24mpg, during the winter, it drops to around 18-20.
good luck...

 

My mileage has never changed with the seasons.

It was June when it dropped from a 22-23 mpg to 17.5-18.5 mpg. I don't think it has anything to do with seasonal fuel. As I said this has never happened before and I've monitored my gas mileage since 2003 on 99% of fill-ups. It has always been steady.

 

Mileage.............?

When ever I have chased this........(the CRV is the wife's car, I usually drive my old Saab), the return mileage has never deviated more that half a litre from 10l/100km. I've driven it hard and I've driven it like a granny..........always averaged 10l per 100km..............go figure?

 

I don't doubt his experience, but this is the type of post that could derail my question completely. I started this thread to see if I could get help with my specific problem/question. I'm still hoping to find the answer I'm looking for. Thanks.

 

I've recently had a gas mileage drop in my 2000 EX. I usually get about 320 miles to a tank and out of nowhere (ironically, AS SOON AS I changed the spark plugs and fuel filter) started getting about 280. I got a check engine light for the front O2 sensor and figured that was the cause...but replacing it has made no difference. It might be in my head...but I've also started thinking that the vehicle feels like it's held back. Not in a runability sense, but almost like the brakes are holding too tight. My rears aren't seized...so I greased the slides on the front calipers. My next thought is the master cylinder starting to go...since I've seen that be the cause of all-wheel brake seizures in more than one civic.

Any input would be appreciated!

 

Hijack many threads lately?

Why don't you start your own thread?

 

Um...you and I are having a similar issue. I was describing TO YOU my similar issue. Read many threads lately? Get over yourself.