check engine light on need more help trouble shooting

I have a 97' ranger 4.0, moderate lift.
I keep getting a PO171 and PO174 check engine codes. the manual says that i'm running to lean.
i have replaced both of the front O2 sensors, cleaned my throttle body, ran a lucas injector cleaner, replaced my fuel filter, and checked my air filter. i at a loss on what to do next. if you have any suggesttions i could use them.

thanks

have you tried resetting everything? (battery)

hey my dads ranger had the same problem i think lol , but anyway if u have the quick turing gas cap check and make sure its tight. we replaced his witht the one with threads and have had no problems since.

Might check for a vaccum leak I believe that would cause it to run lean. My experience with computer codes is they can tell you symptoms but you may have to trouble shoot your self. Just because it gives a code for the O2 sensor dosen't mean that the O2 sensor is bad only that it sensed a problem ie lean or rich. My Ranger gave me O2 sensor codes wich I replaced to no avail. Later found out my fuel pressure regulator was bad. Too much pressure but not all the time but intermitent. Bottom line I had to break down and take it to 2 mechanics first just wanted to replace the O2 sensor wich I told him up front I had just done the other who was sharper put a gauge on the fuel pressure and let it run long enough to see the pressure slowly rise to about 75 psi. Hope this helps in someway. Also Im pretty sure that unhooking the battery in your model wont reset your computer its too new to be that simple if I'm not mistaken. Autozone will pull the codes and clear it out for free.

hey if u leave the battery cables off for around 14 computer will automatically reset and readjust.

I'm trying to figure out how to shut off the alarm part of my remote access on my 1997 Ford Ranger. If I use my remote to lock the doors, then the alarm goes off for no reason. Does anyone know how to just use the remotes to unlock the doors, and not set the alarm? probably re-programming, but how?

I'm also getting a "check engine light" on my 1997 Ford Ranger 4x4. Auto zone said to replace the 02 sensor and gas cap, and reset the system, which I did, and the light came back on. I only replaced one front sensor, so I still have the other to replace, but I'm still not convinced that that is the problem.

I had a similar problem with my '99 3L Ranger. There's a different sensor that I believe regulates fuel-air mixture (I don't think its the O2 sensor but I could be wrong). The sensor's name is a 4 letter acronym which I can't remember, but if someone else knows what it is, it'd jog my memory instantly. The engine would run rough, and rev on its own. It could not be related whatsoever, but thought I'd throw that idea out there.