Need help with engine codes

[mac97]

P1443 auxillary emissions control
P0171 bank 1 lean
P0174 bank 2 lean
P0756 shift solenoid #2 performance

Ive had these for a while now, there's definetly a drop of gas mileage. the first code i have read is the canister purge solenoid? I wasn't sure if one of these codes would throw another one and wasn't sure wich one to start with. My truck is a 1997 4.0L V6 auto 4x4. Any help or input is appreciated!

[mickblock]

The codes will be relayed to the scanner in order 1-4.
Is that the order that they were displayed?

[mac97]

Yeah thats the order they were in on the scanner

[mickblock]

I'm not an expert with OBD but IF there is a cause effect relationship, then it's has to do with that given order, as you suspected.

[mac97]

alright i'll start with the first one and go from there thanks

[southbama man]

The bank lean 71 and 74 means mass air flow sensor. The other I'm not quite sure.

[mac97]

I replaced the mass air flow sensor and it didn't sove that problem?

[ldcater1]

hi, needs purge solenoid and sensor assembly(dealer part) and you will more than likely need upper plenum o-rings. as far as the 756 trans code goes fix the others first then recheck.

[azgilamonster]

http://www.fordrangerforum.com/4-0-s...look-here.html

CHECK THIS
I was told that it is the same on 97 and up by ford tech in phx. but IDK for sure but worth a look instead of parts changing

[southbama man]

When both codes (71 and 74) comes on at the same time it a MAFS. It also could be your 02 sensors on your manifold.

[mac97]

So if it was your truuck what would you start with first, the purge solenoid, o2 sensor on the manifold, or mass air flow? i tried a mass air flow sensor a while back and it didnt clear up the code so i returned it cuz they are not cheap lol

[deanpal513]

Hey, just has the same prob bought a code scaner and it's cool as heck, anyway i was getting the same code bank 1 and bank 2 to lean, after some reading found the rubber elbow under the radeator line sucked shut, also found the last time i had the oil changed at wally world, right below the maf sensor the didnt hook the line comeing into the side where air filter was,,,, anyhow that took care of my prob,,, hope that helps

[fmenghini]

in my case 98 Ford Ranger, 110,000 miles , 4.0 V6 had the error Bank 1 and bank 2 running too lean. Replaced the upper intake(plenum) gaskets. the gasket rings in the plastic upper intake. did not remove the fuel distribution manifold. took some time to disconnect things, not too bad. EGR tube bends forward inside the manifold so lifting the plastic maniflod and shifting it forward to get it disconnected.
got it all back together. Seems to have done the trick. CEL has been off for a few weeks now.

[98rangerxlt]

The 171 and 174 in most cases on the 4.0 OHV is usually upper intake manifold gaskets.