Hi
my toyota camry(1999) has shown check engine light and mechanic has advised me
P0171 system too lean(Blank 1).Then he erased code by doing something with OBD code reader and told me to comeback if it appears again.It never appeared again.
Guys what's going on with my car?
Plse advise

You might have had a temporary glitch in the ECM, air intake, or fuel system that caused the code. Most codes disappear if the condition fixes itself.

You may never see it again but, if you do here's a little more info: http://www.obd-codes.com/p0171