I have honda accord 98 4 cyl with 300k miles, i took it for emission it failed saying it is not ready and i have to drive 100-150 miles and bring it back drove it for 200 miles took it back it happened again. then drove for another 500 miles took it back and it failed again (not ready) . there is no check engine light. someone told me it could be electrical problem which is resetting the computer. It could be as simple as loose ground somewhere or bad computer. can anyone had same problem? any help greatly appreciated.

 

Look at this post.
https://www.hondaaccordforum.com/for...s-codes-28313/

Yours doesn't fall into the 2003-2006 range that I was writing about, but I wanted to illustrate how those readiness codes are not as simple as just "driving 200 miles". And something as simple as a coolant-temperature sensor that reads low can prevent many of them from being set to "ready".