so while driving down the stree from my house the Local Police station has a speed detector to make people slow down. the speed limit is 25mph but when i pass at 25 it shows 20. and in my wifes car its correct. any suggestions

 

My first question would be are the rims/tires the factory size?

 

195/65 r15

 

A dirty VSS might skip enough outputs to reduce vehicle apparent speed. However, this would also cause the mileage accumulation to be reduced. Suggest checking your odometer mileage vs. highway mile posts for 20-30 miles. If miles accumulated are low, then VSS problem seems likely.

good luck

 

thanks guys....while the mileage is at 207xxx im pretty sure your right.