How to Improve the Chances that You Will Pass E Check
A computer code refers to the system that isn't operating properly and not just one particular bad part. You can get a false code from the computer that shows a defective part that is actually working properly.
Computer codes are only about 20% of the information we use to diagnose a check engine light.
We use 4 other tests to diagnose your car problem.
- We interpret the data stream from the sensors to the computer to find incorrect readings.
- We test the ignition voltage readings.
- We test the fuel pressure and pressure regulator.
- We may need to test for a gasoline vapor leak in the EVAP system which can pollute the air.
Here is an example of a code that creates a false reading because it refers to parts that will not cure the problem.
PO401 = Low EGR flow. Code only testers will suggest replacing the EGR sensor and valve. (Exhaust Gas Recirculation)
Neither part will cure the problem if there is a carbon buildup that is restricting the air flow in the system. Parts do not guarantee that replacing those parts will cure your complaint or shut off your check engine light, and they will not let you return the parts.
REAL CURE... Clean the EGR passages and clean the carbon from the engine. If we test your vehicle then we guarantee that the parts we replace will cure your complaint. We also clear the codes from your computer, turn off the light and retest it for other problems.