P0102 and p0420
 

Hey got a 4.3 c1500 v6 1998 2wd. Got a p0102 t changed the maf and temp sensor and engine code came back up. I tested the harnes with a light tester (3 wire pink black and yellow) pink doesn’t turn the light on the tester on, can someone let me know if this is normal orrrrrr is this wire the culprit.