Your check engine light is trying to tell you somethign

One thing that seems certain in older vehicles is that you will see the check engine light. I have seen a lot of people ignore this light as their cars appears to run as good as it ever has but truth is something is wrong. In most cases the check engine light is indicating some emissions related issue or a misfire, other times it could be indicating something much worse. The check engine light indicates that your engine is not running optimally and what ever is causing this should be addressed. Even worse is when your check engine light is flashing, you shouldn't be driving your car when this happens.

To find out the cause of the check engine light being on you will need a scan tool. If you don't own one that is fine as a number of auto parts stores loan them out, or will even do the scan for you. For more information on scan tools see this post of mine. Once you have the code (they have the form of P####, B####, or C####) you will need to figure out what it means. Some scan tools will tell you, but if the one you are using doesn't then you can find out what it means by:

•  Looking it up in a repair manual for your car
• Asking the clerk at the auto parts store
• Looking it up online

If you are going to look it up online I suggest going to this site, or directly putting the code into a search engine like Google and including the make and model of your vehicle as well.You probably aren't the first person to have this problem with your vehicle so by searching for the error code and you make and model you can find out what others did to resolve the problem.

I do like asking the auto parts store clerks as they usually are knowledgeable and if you used their scan tool then you are there already. Sometimes they can provide a detailed printout of what the error code means which is even more helpful. Also you will probably need to purchase a new part anyway which is why the auto parts store lets people use the scan tool for free.

In my experience most codes are caused by old spark plugs (misfire), old O2 sensors (slow sensor, bad reading for a sensor, failed sensor), old spark plug wires or boots (misfire), or some failed sensor (throws a sensor failed code). The good news is that a lot of these issues can be avoided by following a maintenance schedule and replacing these parts before they cause a problem.

Finally in closing let me say that it is always a good idea to solve vehicle issues right away. The check engine light looks the same if you have one error code or 50, and with it on your vehicle is not running as well as it should and may be wasting fuel, polluting, or wrecking other parts without your knowledge.