Code p1490 on 98 maxima v6

What is your question?

Changed 3 parts knock sensor p0325 new maf p0100 changed canister purge valve and cut off valve assembly new hoses and blew out line had cables off for weeks plugged bk up and getting same codes idle a lil at 1st but levels out havent tried to go into gear yet just really surprised have all 3 coded bk....help please

What makes this problem better or worse?

Havent drove it done lots of work just surprised codes havent change

How long has your 1998 Nissan Maxima had this problem?

Bought car for someone else fixing up to drive had codes from beginning