Yesterday, to my dismay, my Check Engine light in my 1998 Honda Passport SUV came on yet again. Lately, the light has kept coming on and going out every so often, and last time I took the car in, the mechanic determined that the car’s computer gave him a “EVAP” code and so he replaced a gasket to fix the problem. Total cost: $70 for the diagnosis, and another $40 for labor. The price of the part was $4.98.
Bogus. They might as well call the light the “Check Money” light.
Today, I decided to put an end to this outrageous price just for diagnosis by buying the CarChip E/X by Davis Manufacturing. This little device plugs into your car’s OBD II port located under the steering wheel and continusly logs data about the car’s speed, RPM, coolant temperature, battery voltage, air intake, engine load, oxygen sensor status, fuel system status, and much more, up to 5 at a time every 5 seconds. It also reads trouble codes given by the vehicle’s computer. The device can hold up to 300 hours of this data. The CarChip E/X lists for $179.99, but I was able to get a cheaper serial-port only version at my local AutoZone for $139.99. The reason why it’s cheaper is becaue it does not support the new CAN protocol used in some cars after 2002. That’s okay, because I have a car made in 1998. My family was interested in using it to avoid the high price for diagnosis for their cars and we split the cost 3 ways, so I get to use it for only $50.
As soon as I got it I put it into my car and let it begin logging. I really just wanted to know what was causing the Check Engine light. When I got home, I installed the software and plugged the CarChip into my computer. Seconds later I found the cause of my problem.
I had a trouble code P0440, which the CarChip software told me was a malfunction in the “Evaporative Emissions Control System”. Wow, that sounds really familar with what the mechanic told me, EVAP. A quick Google search later tells me that it is the system that keeps gas from venting to the atmosphere and it is usually caused by a loose gas cap.
I go outside and check the gas cap. It was somewhat loose. I bet you last time the cap was loose and I was charged over $100 to have a part replaced that was really not necessary. Probably only a quick tightening of the gas cap was required.
I instructed the CarChip to clear the Check Engine light next time I use my car. Hopefully it won’t come back…
The CarChip E/X, like I said before does more than find trouble codes: it also collects a wide array of other cool stuff. Here’s the information it captured as I drove home from work today:
Nice looking, right? Too bad it only runs on Windows.