Check engine light
Source: bankrate.com
Is your check engine soon light on? If so, you might want to know why. An OBDII scanner will point you in the right direction. OBDII stands for OnBoard Diagnostics, the II means it is the 2nd generation. There are 2 varieties, one is a code reader and the other is a scan tool. The scan tool allows you advanced troubleshooting data.
The scan tools gives you many more useful features such as bi-directional controls and the ability to monitor the data. But these features come at a price. High end unit cost upward of $10K. For the DIYer, a good scanner will run about $100. Another tips is to find out what scanner is compatible with your car. An OBDI scanner will probably not work with an OBDII car. In 1996 the OBDII was made mandatory for cars in the US.
This is a basic scanner
Source: wikipedia.org
This is a more advanced scanner
Source: wikipedia.org
When an engine malfunctions a trouble code is sent to the on board computer. This code is stored and can be read. The code is usual in the format of 'P0000'. Once you know the P code, there is a list of what that P code is referring to. These lists are readily available on the internet.
To use the scanner, locate the connection port. It is likely found on the drivers side under the dash. Below is a photo of the port. Just plug the scanner into the port and turn the ignition to the on position (the lights on the dash will illuminate).
Source: wikipedia.org
If you live in a state where you are required to get a smog test, an illuminated CEL (check engine light) will guarantee that your car will fail. A scanner will also clear the codes and the CEL will go off, but this doesn't fix the problem. There are about 7 tests that the engine completes, if these test are incomplete you will fail the smog test. You will need to run the car for a few miles for the tests to complete and if you just cleared the codes, the CEL will come back on after the tests are completed. A reputable smog testing station will tell you that they can't do the smog test until your car completes this battery of tests.
If you don't want to do the work, knowing what the problem is will help you see if the repairs your mechanic tells you are needed fit the problems. Thank you for reading.