ok so since ive had the car recently the code p1259 was been there. i notice that when im driving around 2000 rpms and i dont give it any gas it automatically takes the rpms down, like it will fluctuate inbetween 2 and 1k rpms..any idea which part of the vtec system it is?

and a new code p1456 has just came up ..any idea what i can do to fix it?