1987 supra
 

I am having fit trying to get my son's 87 supra to pass emissions. I had passed everything but the CO which I heard was fro a rich mixture. I check the injectors and found out they were the green tip ones for a 89 supra. I ordered the yellow tip but they didn't fit the connectors. I filed off the grooves and they fitted. Installed a new remanufactured Airflow sensor and a new pressure regulator and had it retested. It failed worse then before. Can't figure out what gives. Any help out there?