Your check engine light comes on. Panic sets in. What do you do? You call the shop, dreading what they are going to say.
"What do you charge for diagnsotics?" you ask.
"Testing starts at $95 for a check engine light" the service advisor responds.
GASP. Why so much? Can't I just go to AutoZoom down the street for a free test?
Here's what you're paying for:
"For example, the P0503 code, which indicates a malfunctioning vehicle speed sensor, has forty-one steps spanning eleven pages in a shop manual after the code has been set. Examining those forty-one steps takes time and expertise to examine"
The code pull is just the first step. The rest of the story happens while we test different sensors and systems to find out which one is the culprit. The sensors are dumb, they report what they see, not what the cause is. You may have an oxygen sensor that is reading out of range, but is that because the sensor is failing or is there a problem further up the line? Instead of replacing parts based on codes we replace them based on testing, a much more efficient way to do things.
You are paying for the technician's time, expertise, and the thousands of dollars in equipment that it takes to perform these tests. You don't expect the plumber or electrician to show up and tell you what's wrong in your house without paying for their time, nor should you expect the mechanic to spend time with your car for free.
We've had many customers come in after replacing parts based on recommendations from the local parts store based on a check engine light code. They had already spent hundreds of dollars on parts and installed them only to have the same issues as when they started. Had they come to us first and paid for the testing and repair they would have spent less than they did on the unnecessary parts.