Was fiddlin around the net this morning and came across a site that was saying on Rangers the o2 sensor should be changed every 100k miles regardless of whether your check engine light comes on or not. It said something about even if it hasn't failed it will increase mpg.

True or false?

 

common sensr its true.

replacing all parts that arent broken will get you more miles just because they are clean and perfect.

replace with brand new 2.5L and enjoy return in power and miles