Nissan Repair: 96 240sx, readiness test, negative battery

Question
My 96 240sx is just about sold and I need to smog it. the problem is it wont
pass due to being stuck in the readiness test mode. im using a mac tools
code reader and it just told me that I had code p0440. I have driven the car
with no check engine light for over 300 miles to try to get the CEL to pop on
or pass my readiness nest.  and it did niether.   I havent got the code to come
back. im stumped.

Answer
Hi Nigel -

How about trying to reboot the computer? Remove the negative battery terminal for at least 30 seconds and replace it.

If that does not work, try using another code reader. I don't think you have any car issues.

Hope this helps -
calvin