I have a 2000 Dodge Durango. I replaced the spark plugs last week. Then I replaced the upstream 02 sensor and got rid of code P0131 but now it is showing code P0171 and blowing some black smoke. Does anybody have any suggestions of how to fix this.

 

check your fuel pressure at the rail, and maybe run a tank of fuel injector cleaner through it (try seafoam)

did you get an OEM o2 sensor? if not that could also be causing the problem, it is what controls the mixture anyway

 

Symptom List:
P0171-1/1 FUEL SYSTEM LEAN
P0174-2/1 FUEL SYSTEM LEAN
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0171-1/1 FUEL SYSTEM LEAN.
When Monitored and Set Condition:
P0171-1/1 FUEL SYSTEM LEAN
When Monitored: With the engine running in closed loop mode, the ambient/battery
temperature above 20 deg. F and altitude below 8000 ft.
Set Condition: If the PCM multiplies short term compensation by long term adaptive and
a certain percentage is exceeded for two trips, a freeze frame is stored, the MIL illuminates
and a trouble code is stored.
P0174-2/1 FUEL SYSTEM LEAN
When Monitored: With the engine running in closed loop mode, the ambient/battery
temperature above 20 deg. F and altitude below 8000 ft.
Set Condition: If the PCM multiplies short term compensation by long term adaptive and
a certain percentage is exceeded for two trips, a freeze frame is stored, the MIL illuminates
and a trouble code is stored.
POSSIBLE CAUSES
FUEL FILTER/PRESSURE REGULATOR (HIGH PRESSURE)
KINKED/RESTRICTED FUEL SUPPLY LINE
TPS VOLTAGE GREATER THAN 1.1 VOLTS WITH THROTTLE CLOSED
FUEL PUMP INLET STRAINER PLUGGED
FUEL PUMP MODULE
MAP SENSOR (OUT OF CALIBRATION)
TPS VOLTAGE CHANGE NOT SMOOTH
ECT SENSOR (OUT OF CALIBRATION)
FUEL PUMP CAPACITY (VOLUME) OUT OF SPECS
ENGINE MECHANICAL PROBLEM
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRB, read the DTC’s.
Is the DTC Specific Good Trip Counter displayed and equal to zero?

 

the black smoke (rich) and the P0171 (lean) are contradictory.

i think your o2 is sending a false reading to the pcm, and its set fuel to full rich, and its still reporting lean.

did this problem start only after you replaced O2, if so something is wrong with your o2 or you wiring.

 

I agree.


Replace the upstream 02 sensor with one from the dealer as it sounds bad. Run Champion Copper Spark Plugs.

 

The Durango isnt blowing smoke after I ran a bottle of seafoam through it. I cleared out the codes but P0171 has popped up again. From what I am reading, sounds like I need to do some checks on the fule pump? I'm guessing that its not the o2 sensor since that code isn't coming up since I changed it. Thanks for all the input.

 

if you used an aftermarket o2 sensor that is likely to be the culprit (if you didnt buy it at the dealer, you screwed up)

 

Just replace the upstream 02 sensor and be done with it.