Hey guys,

New here and hoping someone can help me understand this issue. Today, my truck had a hard time starting but it did start. My quad cab Dakota has 54768 miles. It was not driven that much for the past two years. In the past few weeks as we have been driving it, it has been stalling and today the check engine light finally came on. I bought a code reader and the two that came up were P1129 and P1128.

The guy at the parts store sold me some Mass Air Flow cleaner and some ethanol fuel cleaner and told me to put a third in my fuel and some in the crank case.

Any ideas on what this may be before I take it to dealer? Is it something I can resolve?

Thanks in advance!
CJ

 

Welcome to the forum. If it has been sitting for a couple of years, you could have some bad gasoline. I would also check for vacuum leaks. Clean the throttle body, maybe pull off the IAC and TPS and clean those too. You can remove the throttle body by taking out 3 or 4 screws. MAF cleaner wont do much good because these trucks dont have one. Whoever sold you that did not know what they were talking about.

 

These are codes from a Dodge Ram Hemi, I'm not 100% positive that they apply to the Dakota 4.7.

P1128 - CLOSED LOOP FUELING NOT ACHIEVED - BANK 1
P1129 - CLOSED LOOP FUELING NOT ACHIEVED - BANK 2


When Monitored:
Engine running in closed loop mode.

Set Condition:
Enable conditions are met and the 02 sensor has not been in closed loop control at least once on each of the two consecutive trips, the MIL illuminates and the DTC is set. Two Trip Fault. Three good trips to turn off the MIL


Possible Causes

RESTRICTED FUEL SUPPLY LINE
FUEL PUMP INLET STRAINER PLUGGED
FUEL PUMP MODULE
O2 SIGNAL CIRCUIT
O2 RETURN CIRCUIT
O2 SENSOR HEATER OPERATION
O2 SENSOR
MAP SENSOR OPERATION
ECT SENSOR OPERATION
ENGINE MECHANICAL PROBLEM
FUEL FILTER/PRESSURE REGULATOR (HIGH)
PCM


Technical repair information here

 

Cj,

Similar to what is posted above with a few differences for the 4.7. See below.

P1128-CLOSED LOOP FUELING NOT ACHIEVED - BANK 1

P1129-CLOSED LOOP FUELING NOT ACHIEVED - BANK 2

• When Monitored: Engine running in closed loop mode.
• Set Condition: Enable conditions are met and the 02 sensor has not been in closed loop control at least once on each of the two consecutive trips, the MIL illuminates and the DTC is set. Two Trip Fault. Three good trips to turn off the MIL

Possible Causes

RESTRICTED FUEL SUPPLY LINE
FUEL PUMP INLET STRAINER PLUGGED
FUEL PUMP MODULE
O2 SIGNAL CIRCUIT
O2 RETURN CIRCUIT
O2 SENSOR
MAP SENSOR
ECT SENSOR
ENGINE MECHANICAL PROBLEM
FUEL FILTER/PRESSURE REGULATOR
POWERTRAIN CONTROL MODULE (PCM)