i have been having some problems with my car and i cant really figure out what it is does anyone know what could be the problem.

Problems and trouble codes:
Loss of power
Rough idle; idle drops all the way down and almost stalls.
When driving, put in to neutral and start braking car stalls.
Error codes: system too lean (bank 1), random cylinder misfire, cylinder 2 misfire
Sometimes when accelerating car jerks and surges a little.

all these are different problems i have been having and i tried fuel system cleaner and cleaning the Maf sensor.

I was thinking it could be any of these but im not sure, any ideas?

Spark plugs
Ignition coils
Fuel injectors
Vacuum leak at intake manifold or vacuum hoses
Fuel pump