Hi all,
New to this board and was hopping for some info & help.

Everything started few weeks back. First engine light came on and after getting my hands on ODB it showed O2 sensor, which has been replaced.

Now I get new error.
P0127 (P0172 System too Rich (Bank 1)) and most importantly car stalls on low RPM. When I say stalls, I mean engine simply turns off, but can be easily started and driven.
MAF has been cleaned and other then stalling engine rungs good and strong?

So my question is? what to do to fix 0127, and could it be a fuel pump. Since it stalls every so often on low RPM the only thing that comes to my mind is pump ?

Any ideas??

The ride is 4runner 1999 3.4L engine.. California version 2x4

 

You may actually need to replace the MAF instead of just cleaning it.
If that fails, then you're looking at needing a new O2 (A/F) sensor.
Change the MAF, pull the neg batt terminal to reset codes then drive until you get another CEL.