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“Now you can find out what’s wrong with your car…no need to go to a dealer or repair shop. This CAN OBD II Code Reader/ EOBD Scanner “reads” your car’s computer to tell you what the issues are. Your vehicle’s OBD II system monitors emission control systems and key engine components by performing either continuous or periodic tests of specific components and vehicle conditions.” Freight Harbor website.


Doesn’t this sound great? If only it were complete true! Or course, it is not.  Code readers / scanners are just that. They tell you what system is being affected, NOT what the problem is with the system.  PO171 and PO174 are common Ford product codes we see in our shop. We also see many angry people who replace their vehicle’s oxygen sensors because the codes “told them to do it”.  Unfortunately for them the codes “lied”. They have a vacuum leak somewhere in the system causing the sensor to read incorrectly. They have now spent hundreds of dollar on what could have been an inexpensive repair.  Automotive technicians invest in the proper tools and training to help you keep one of your most prized investments in top condition. In the long run this could save you thousands of dollars and the headache of having to buy another car.


Code readers that clear the codes often give a false since of security to the end user: “ I cleared my codes and the light did not come back on for 100 miles so it must not be a big deal”.  Your vehicle’s computer system monitors emission systems which controls your fuel system and with today’s fuel prices it is wise to invest in the proper repair of vehicle. Unless you have a full understanding of your vehicles complicated computer system you should seek professional help.


A quality shop will not charge you to pull codes for two reasons: it is the first step to knowing what systems need to be tested and  it does not tell you what is wrong with the vehicle. You should be asked to come in; have the codes pulled; and then discuss if you need testing now or may need it later.


Shops invest in high tech scanners that are able to perform many necessary tasks that your parts store scanner cannot perform.  Your scanner may only be giving you part of the information needed to make an informed decision. Would you jump in to water without knowing if there are sharks in it first?