Someone tried to steal my car. Changed the main ignition system assembly. Assembly did not have immobilizer. Car will not start even when had locksmith try program new keys that came with the new ignition system assembly. Original immobilizer
was cracked. 2002HONDA Accord LX
3.0V6

 

At this point, I would get an immobilizer bypass chip, solder it in, and be done with it. Then your keys will work without programming going forward.
https://www.ebay.com/itm/Immo-Emulat...Cclp%3A2334524