A few questions regarding
P0171 -- System Lean Bank 1:
If there is a problem with the fuel-air ratio, which this is basically about, why is it limited to only one of the two engine banks of a V6?
Are there guidelines/heuristics to determine whether the cause of this is air intake (such as dirt around the MAF sensor or vacuum leak caused by a hose puncture) or the fuel pump is weak inadequate? Since I am also getting
P0101 - MAF, I am inclined to think the former. I replaced the MAF sensor a couple of months ago so it shouldn't be that.
I noticed the fuel efficiency is slightly off. Could this be the reason why?
How safe is it to drive the vehicle?
Other than the CEL and 3. above, the truck (2007 Tacoma V6) is running fine.