Sr20det mising?, but leaning out?

[mikesloud]

I need help , I have fuel A/F on wide band at idle or light throttle, at 13.9-14.2 and it sounds like a miss or too lean , sound. If I run fuel at 12.2-11 it goes away. It does not do it all time, at cold start, it mostly won't do. any ideas? what should I check? I am using super afc 50lb injectors z32 ?