Odometer Problem

[musicislife]

I noticed a while back that the gas mileage for my '96 Camry was going way up. I started to pay attention to the odometer while driving and noticed that it was spinning too fast. I checked it against the mile markers on the highway and then with a GPS. It appears to put 1.67 miles on the odometer for every one mile I drive. The speedometer is close to correct, so I'm assuming that the speedometer and odometer don't really have anything to do with each other.
I disconnected the computer from the battery and let it sit. That seem to correct it for a day or two, then it went right back.
The car has 204k miles on the odometer. It probably really has just under 200k miles. It has the same wheels/tires it's always had.
Any idea what's going on and what I can do about it? It's almost as if it's converted itself to reading kilometers instead of miles.

[carsrus]

Does your 96 have a analog or digital odometer? If its digital im stumped. Might be the speed sensor, but im pretty sure the speedometer would be whacked out too then.

[Nervous]

Never heard about 96 Camrys with digital odometer....

[musicislife]

It's an analog odometer.
In the old days a cable went from one of the wheels to the speedometer/odometer. The cable spun a series of gears. What makes the odometer work in this car? Is it controlled by the computer? I've seen other posts on here asking about changing a Canadian Toyota from kilometers to miles. Is that possible without changing out the speedometer/odometer? Is it something that can be programmed?
I'm just so used to the odometer being strictly mechanical that I can't get my head around why it would be spinning faster than normal.