01 ranger codes p0172 and p0174

CEL light on and codes of P0172 bank one too rich, with possible causes of MAF, Oxygen sensor, ignition misfire-repair, fuel injector problem and P0174 bank two too lean. Please offer any advice.

if the cel is just on and it runs ok then it probably is the oxi sensors which need to be changed around 70,000- 100,000 it most likely is the oxi sensors.

if it runs a little lousy it can still be the oxi sensors but i would first try cleaning the maf with a electric cleaner. do the oxi sensors. then replace maf if that dont help. then move on to the other two.

Had the same CEL indication on my 99 Ranger 4.0L. All the components you have mentioned are possibilities however arrange the options in order of complexity. To make a long story short, I developed a slight leak in the upper intake manifold which caused to computer to sense a lean mixture. I replaced the "O" ring in the manifold and that solved it. At least as the result the code went aweay and has not reappeared. Just for drills, try squirting injection cleaner around the base of the intake manifold while your engine is idling. if you have a leak, even slight, it will affect your idling. If that don't solve it, then you may check other possibilities.

I have a 98 ranger 4.0 coputer codes 0174 mixture too lean. What could be the problem?

Since its only in one bank (0174), it's not a manifold leak. Check out the pre-cat 02 sensor for that bank and/or any of the injectors on that bank.