Remember this photo from this summer? I post it again because megan came down last night for some post test relaxation (Who Framed Roger Rabbit) and on the way down here check engine light came on again but this time we were able to take it to the auto parts store and have it read! Yay! It was code number 32 that means the EGR valve is not working. This is a little frustrating because I replaced the same valve this summer at a cost of over $100. Good news again is that it has a 1 year warranty so they will give me a new one.
The EGR valve's job is to help reduce NOx (nitrogen oxide) emissions - a prime cause of smog. At high operating temperature (warm engine, lots of RMS) NOx will be formed. To prevent this, the engine sucks in some exhaust to act as an inert gas and prevent the formation of NOx. What it happening here is the valve is sticking open, so at low operating temperatures it is still sucking in inert gas and that is starving the engine for air and causing it to hick-up.
This has been your car 101 for the day.