ok here goes....gotta ls/vtec with b16 head....p30 del sol vtec ecu...vtec will not engage....its throwin codes 21 vtec solenoid....23 knock sensor...and 43 primary oxygen sensor-heater....does the knock sensor code have anything to do with vtec not engaging?...and how would i fix the code 21? i was told to clean out the screen on the solenoid itself so im gunna try that....if that doesnt work what else might take away that code?