But I'm hoping this may help.
http://www.autocodes.com/p0171_toyota.html
I'm sure your mechanic checked these, but you may want to run it by him again to ensure he did.
Good luck!
-Lee
I have a 2007 Toyota corolla sport, and the check engine light came on a little while ago. I ran the diagnostic and it gave me "bank 1/system too lean". However when I took it to my mechanic and told him about this he ran tests himself and said he couldn't find one thing wrong with the car. After I got my car back I drove it for one day and the check engine light came back on. What should I do?
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