im throwing a primary O2 sensor code in my 96 civic coupe. Its all converted over to OBD1 (92-95) and im running a 1995 p28 ecu. Wut would cause this code to throw? defective sensor or like air?fuel mixture is off???? it usually comes on when im in 3rd gear right before vtec engages....and it comes on all the time when my air conditioning is on.......ANY HELP????