I have 4.11 gears in my mustang and I bought the gear from steeda to correct the speedometer and it helped but it is stil 10-15 miles per hour off. The tires are the stock size tires, they are 245 45 17's. The car has a speed sensor, does that make a difference in the recalibration? What else can I do to make the speedometer more exact, if I unplug the speed sensor will that make my odometer quit working or the cel to come on. I want to stay under 5000 miles for the emissions exemption and I figured unplugging the sensor would be easier than unhooking the gear if it will work and not cause any problems.

Thanks, Dave

 

what gear do you have in it and is it 10-15 over or under?

 

It reads 10-15 mph too fast. My odometer records more miles than I really drive. Thats why I was wondering about just unplugging the speed sensor. I didnt know if this would set off the cel or not. I have the white steeda 23 tooth speedo gear.

 

sounds like you need a 21 tooth gear