So yesterday the dreaded Check Engine light came on as I drove home from the Children’s Museum. The CEL, of course, can mean anything from "You didn’t put the gas cap on tightly enough" to "A tiny, $600 sensor crammed in an inaccessible spot has failed."

This is bad for a couple of reasons. Obviously I’m in no mood to shell out $600 to fix anything, and further, I don’t have a good mechanic around here yet. Luckily, though, I have this neat device called a CarChip that I received from the manufacturer a few years ago.

It was marketed as a way to keep track of a car’s usage. (Parents of new drivers, take note.) It plugs into your car’s ODBII connector (an easy to find thing under the steering wheel) and records things like speed, acceleration, engine speed, etc. You can then plug it into your PC and get fancy graphs and such. I often fantasize about getting a speeding ticket and using the CarChip as evidence I was going the limit.

Anyway.

One of the other things the CarChip can do is record any diagnostic codes the engine throws out — i.e., that "Check Engine" can become something more meaningful. So I did this. The problem code was P0401. Then I hit the tubes of the Internets and Googled "Toyota CEL P0401."

Presto — tons of links and help. The problem is most likely one of four things:

A) An inexpensive and easy-to-reach part needs to be replaced;
B) A different easy-to-reach part need to be cleaned;
C) A $150 easy-to-reach part needs to be replaced; or
D) A $400 hard-to-reach part needs to be replaced by a mechanic at $65 per hour

The good news is that my other symptoms — the engine occasionally revs while on the highway — make it most likely that it’s A. But we’ll see. I reset the Check Engine light (another thing the CarChip can do) and took The Boy to school this morning. It didn’t come back on. If it does, I’ll have an idea what to do.

Of course, now I have to find an auto parts store around here….