99 Ford Ranger XLT, 4.0, automatic, 4x4.
Im having some issues with finding out what is wrong with my truck. it throws codes 0174 0173 saying bank 1 and 2 running lean. Checked intake gasket, maf sensor and air box and black tube. Nothing. Its getting about 9 mpg or 160 to 180 miles to 16.5 gallons of gas. Ive heard fuel pressure regulator? Vaccum lines behind motor? Cant find the problem and ist driving me nuts. Doesnt have rolling idle or anything idles great. Please Help!!

 

Winter blend gas. They add in 10-15% ethanol and you get crap for milage. Its happening to all of us.

 

Check your fuel pressure, have you ever changed the o2's? Also fuel injector cleaner once in a while will help.

Sadly 11mpg is about the norm in this cold weather. Last tank I did 14 but, I did not let the truck warm up at all before I drove. If I let it warm up 5-10 I will be in the same 10-12 mpg range.

 

never checked 02s but the computer says theyre reading right when its running. Before winter though it was still doin bad.

 

im assuming you have a SOHC. these codes come up. generally the consensus is this....



i had the same issues and changed everything!!!(except the 02's) this is what it turned out to be. the rubber elbow had cracked on the bottom of the hose and was causing unmetered air into the engine causing it to run rich and still not compensate for the extra air in causing both codes.

 

99 has the ohv.

 

hahaha this are my thoughts exactly. I went through a tank of gas in 2 days of normal driving. true story. truck still does this. threw a 20 in her on the way home again since sunday

 

Sounds like you have an 02 sensor issue. 10-15% is the normal ethanol blend all year, cold temps require more fuel, although not as much fuel as you're using. I'd check 02's and go from there

 

It might throw the 02 sensor code, but also check your intake plenums. My OHV threw the 02 code, then once I replaced them, it came back on. Turns out it was the plenums that had hardened up and started to leak. Just a heads up.