System too lean bank 1. I'm guessing bank 1 is the intake side not sure tho. Also the car has a k&n intake on it not sure if that would cause a problem or not. What your thought on this fellas?
Bank 1 is the only bank on a 4-cylinder. If you get a "bank 2" code you've got SERIOUS problems, LOL.
An IAC problem won't throw a lean code.
90% of the time it's a vacuum leak. PCV valve, intake manifold gasket, vacuum line, brake booster... something post-MAF. That's the most obvious starting point.