So, my truck failed badly on the last smog check. Cat was dead, for one, and the HCs and CO was way high. I replaced the cat along with the rest of the exhaust and since the truck had sat a long time before I got it I decided to clean the injectors. Turns out the injectors in the truck were 208cc/min injectors. Stock flow is 185cc/min. 13% higher rate that stock. So I installed a set of stock injectors and the HCs and CO dropped drastically. In the idle and 2500rpm test the HCs are now in the single digits and the CO is 0.00%.
Found out these injectors are offered as an "upgrade" being a 4 hole injector instead of the stock 2 hole. Makes sense as the 4 hole design does have a finer mist, but the stock ECU just can't compensate for 13% more fuel. Newer, OBD2 ECUs can handle it, but not our older, dumber ECUs. Might be able to use them in my MR2 though.