Honda Repair: OBD Readiness Result: Failed, honda passport, fuel sending unit

Question
I have a 2001 Honda Passport that HAD the fuel guage reading low issue and was failing inspection. I replaced the fuel sending unit on the fuel pump myself and it is working great. I bought the sending unit on Ebay for under $40. But the vehicle is still failing the OBD READINESS test. I was told by a mechanic that since I disconnected the battery I will have to drive the vehicle a few miles to reset the computer. I have not driven more than 100 miles before the inspection failed.  Is this true? Does the computer need to reset itself? Will it do it by just driving the car?
I guess my real question is, why is the vehicle still failing the OBD READINESS test?
???

Answer
Hey F,
To be honest with you, I'm not 100% familiar with the inspection process, but if it is still failing I would take it to a reputable shop and have them reset the ECU with a scan tool as opposed to unhooking the battery. Good luck and let me know how it works out.

Jeff