I have an 01 Dakota with a 4.7. My problems started a few weeks ago. It began as a starting issue, had to crank over several times before it would start then it acted like the engine was loaded up when it did start. it would clear up quickly and run fine. I changed the plugs because of a misfire fault. It was still hard to start but ran very well for about 3 days. Now it is not only hard to start, but it chugs when in gear until the rpms get to about 1800, then has better power, and tops out at 4000 rpm. I have several codes showing- 031,051, 151, and recently 1281. I have replaced all 02 sensors, cleared the pcm, and still no change. Anyone ever have this problem?

 

P0031 is 1/1 O2 sensor heater circuit low
P0051 is 2/1 O2 sensor heater circuit low
P0151 is 2/1 O2 sensor shorted to ground
P1281 is engine is cold too long.

What brand of O2 sensors did you put in? Why did you change them in the first place?
It could indicate a short in the harness, bad connection, heater circuit fuses, or a bad PCM. Disconnect the battery and pull the connectors on the PCM and check for oil. A bad power steering pressure switch can leak and oil can/will wick along the wires.

P1281 is likely a bad thermostat OR you put in a 180 degree.

 

Bosch. I replaced them because of the codes that were being read. The power steering pump has started whining recently, I will check the harness for oil.

 

Check the harness and connectors then get rid of the Bosch O2 sensors.

If you look through this forum you'll find out that almost everyone that has used them has had problems of one kind or another. NTK or Denso are recommended and OEM.

 

Where is the wiring harness?

 

For the oil? The wire harness that leads to the PCM. Pull the connectors, if you find oil it needs to be cleaned.

 

 

Open the hood, look left on the inner fender. It's a rectangular box and has 3 connectors on it.

 

I fat fingered the key board. Code is p0152 not po151.

 

P0152 2/1 O2 sensor shorted to voltage

There is a very good chance most of your issues are due to Bosch.