The odometer only works when the speedometer is engaging. With the old speed sensor installed it was erratic. With the new speed sensor installed, it works, but reads more slowly because it thinks I'm driving everywhere at 10 to 15 mph.
On some vehicles you need to program pinion factor which takes in to account tire size and gear ratio. Not sure I found that applies to your vehicle. That programming feature may be available on the code readers at the auto supply. Your larger independent repair shops have the electronic tools to do that.
