hello:-)

ive recently came across this error code, after repairing several others. minor things such as wires, plugs, filters etc. ive come to understand that it may be running too lean, this p1131 will usually never gave me problems until several days ago(stalling). what may be causing it? if its the o2, any idea which one would cause a stall? possibly a vacuum leak? or maybe even a clog fuel injector that may be confusing the computer to think its too lean.

p.s p1131 is the only error code that comes up on the diagnostic.

id appreciate any advice or things i may have not look upon.
thank you and cheers

Tucker