You’re driving down the road and all of a sudden the check engine light comes on. Oh no! What do you do? Well, unless it is flashing or you heard a loud clunk, you might as well keep on driving.
Such a scenario happened about 2 months ago while I was driving our 14 year old car around town. The check engine, or in some cars, the service engine soon light simply means that at your next earliest convenience you should have your car checked out.
The great thing is that you can do this for free. Just head on over to the nearest Autozone, Advanced Auto Parts, or any of the DIY centric car parts stores. Most of them will offer a free service where they connect a small handheld device to your cars OBD 2 port. OBD stands for On-Board Diagnostics. This nifty port, located by the drivers left knee, allows handheld diagnostic devices to talk to the cars computers. The cars computer will have stored a code and that code helps explain why the check engine light is on.
In my case, I had a code P0440. You can either look that up on the internet when you get home, or the store employee can usually print out a list right there at the store explaining the code and possible fixes. P0440 is an Evaporative Emission Control System Malfunction and while scary sounding, all it really means is that gasoline vapors were leaking out of the fuel system somewhere.
Unless you live in an area that mandates emissions tests on vehicles, you can safely drive for another 50k+ miles and suffer no consequences except a slightly worse fuel economy. There are a number of potential causes and fixes for a Evap Emission and the printout should list them. The only simple fix that doesn’t require a lot of speciality equipment was to replace the gas cap. So that’s what I did.
About a month later the light turned off all on its own. Yay!