I'm getting a lean code for bank 2 and a random intermittent misfire. The truck has been having a slightly rough idle and dropping rpms randomly. It does it when in park and sometime when i'm stopped and switching gears. I have a new fuel pump, sparkplugs, air filter, and cleaned throttle body. Also has a new fuel pressure regulator. I cleaned the idle air control valve. I also as having problems with similar codes and replaced the mass airflow sensor and it made it run much better for a couple weeks then this problem came. I've heard it might need new idle air control valve but wanted to hear what other people thought.

 

check your intake manifold gasket for leaks. this can cause a system to run lean

 

yep but only at idle. so use this information to prove out manifold leak. if the fuel trim is adding at idle but within 10% at 2500rpm...you have a vacuum leak

check the fuel trim( whenits in closed loop and not misfiring) and confirm the fuel trim is lean on one or both banks
if its lean all the time, its not a vacuum leak. check fuel pressure.