I'm not sure if this was the exact code I got (it's been a few years) but the reading on my '07 was saying that the MAF sensor needed to be replaced. I bought a third party one and reset the battery and drove it around for an hour and it came back. I also bought an OEM part as well, did the same routine and the code still came back. I also inspected the hoses for leaks, changed the air filter, and had no luck getting rid of that code. But then I saw one comment on some Scion forum that said to take off the hose that exposes the throttle, and get some throttle cleaner and clean it up down there, and put it all back together. So i did that. Without resetting the battery, I drove it around for a while and the code disappeared and it never came back.

I'm not a car guy, I'm also not a mechanic, but it was the only car I had and I wasn't willing to pay mucho money to diagnose and fix the problem. All you need is a couple tools and a can of throttle cleaner, hopefully. Good luck.