i researched what codes my ecu are throwing. im getting 2, 21, and 23. 2 is my 2nd o2 which ill have to check if there is one on my car. i just recently got it and im trying to go over the whole car little by little. its a crx with an obd0 ecu and a b16 turbod. what im trying to get to is code 21 which is vtec spool selenoid valve. what can i do to try and get this code fixed. on to code 23 which is knock selenoid. what can i do to fix both of these codes??? i wanna try to get rid of them before putting my obd1 stuff in and gettin it tuned. please help me!