I have been diagnosing this for a couple months now. Moved across the country in the meantime. Said it was running rich. I was trying to not do the MAF sensor because they're expensive. Checked the Coolant Temp sensor, vacuum lines, and spent way too much time finding the correct voltage for the MAF at idle. Turns out it wasn't too much time. I got an incorrect reading off the MAF, replaced the internal sensor part with one from Bosch, It fixed the code and the reason I always had to crank it twice after it sat for a day or more before it started. Starts first time every time now and the CEL is staying off. Bring it on winter!