We’ve done quite a few blogs on this issue, but it is so common that people really should know what to do as well as a few of the things that can cause the problem.  In general it is okay to keep driving in the short term as long as the check engine light is not flashing. In the longer term the problem should be properly diagnosed.

The first step is to run a computer scan.  The results from the scan will determine the next step. It could range from something as simple as tightening the gas cap to something as complex as taking the engine apart. Just because there are no symptoms does not mean the drivability and emissions output are not being effected.

Recently, Ben, one of the skilled technicians at BA Auto Care shared two photos related to a check engine light problem on a 2004 Honda Civic. The scanned computer data that was downloaded by Ben pointed to a blocked exhaust gas flow in the intake manifold. This problem could cause pre-ignition and increased nitric-oxide emissions which in turn could
lead to LESS miles per gallon.

A part of the intake was removed and it was clear the passages had become blocked. The passages on the left are clogged with carbon. The photo on the right shows how it should look after the carbon has been removed. After reassembly the computer system is reset. Once the computers are reset, they will automatically test the system. It takes a couple of days for the computer monitors to gather all the necessary data.  If all is well, the check engine  light will remain off.

If you ever have to have a repair like this performed make sure the repair facility documents the codes that caused the check engine light to come.  That way, if it does come back on in the future you will know if it is related to your last check engine light repair.