I am having the same issue with a repeating P0507 code. I haven't found any vacuum leaks. I have cleaned the throttle body, replaced the throttle body gasket, replaced the idle air control valve and gasket, replaced the PCV valve. I cleaned the EGR passages in the intake manifold. I don't think the Element has an actual EGR valve.
I read through your list of things to do to fix this problem and have a few questions:
1. Where is the EVAP vent valve?
2. What are the basic settings/reset adaptions of the throttle body?
3. Can you explain how a faulty power steering switch would cause this particular code?
Any information you can share with me will be greatly appreciated as I am getting quite frustrated with figuring this problem out.
My Element is a 2005 EX, with a manual transmission.
The symptoms are occasionally a "hunting" idle and the car lurching when the the throttle is let up on (more noticeable at lower speeds). The lurching has noticeably improved since replacing the PCV valve. It still occasionally "hunts" for idle, usually after being driven for awhile, not when engine is cold.
Thank you and I look forward to any suggestions you may have.