Rough idle and lean code(s). Sounds kinda familiar on another thread. After much work and parts replacement the OP found one of the connectors to a fuel injector was popped off. And I recall another recent thread with the same type issues after a MAF conversion, one of the injectors was not firing.

With no fuel injected into one of the cylinders the fresh air in the exhaust was fooling the computer into a supposed lean condition.

 

I ordered some reman injectors, throttle body gasket, valve cover gasket, and upper/lower intake manifold gaskets. Hopefully this will take care of it.