58K miles on the accord and the MIL came on.

The loaned OBD2 scanner from Autozone reports the following error code twice:
P1164
The message is something liek: Manufacturer's control Air Fuel ....something like that.

I guess the error code is good enough to kind of narrow down the issue....btw, i believe that the MIL turned on while i was driving the car normally the way i do.
What can be wrong? How much will the parts cost? I would like to fix it myself and save me some money. I am not a auto mechanic but definitely am the curious types looking for a project over the weekend.

 

MIL? do you mean check engine light

 

yes

 

MIL = malfunction indicator light, or something like that... same thing as CEL.

P1164 = Primary heated O2 sensor circuit range malfunction.

Sounds like you need a new O2 sensor.

EDIT for elaboration:
Prices vary for O2 sensors, depending on if you go with OEM, universal, Bosch, etc. Expect anywhere between $40 and $125 (?), depending on which you go with. It's relatively easy to change yourself. You can rent/borrow an O2 sensor socket from Autozone for a fully-refundable deposit. The sensor is located at the bottom of the exhaust manifold. You can see it sticking out towards the passenger headlight...