Starting to have the same symptoms once again. Truck really has a mind of its own. Today my truck has thrown the following codes PO141,PO135,PO138. I pulled the intake mani sensor an cleaned, i pulled out IAC an cleaned it (wasnt very dirty at all) also cleaned TB port. Every sensor is mopar from dealer. Today i replaced front 02 with another denso which seemed to make the truck run fine minus the codes it threw when i got back into my driveway.
While i cleaned those items an replaced the 02 i diconnected both +,- an touched them to each other to drain the power system. Besides the codes it threw the truck seemed to run good i usually get this type of weird idiling on the first cold start of the day. I will know tomorrow if it decides to act up again.

yes some may wonder how this issue can go on for so long an the only answer i have is it comes an goes. You may have noticed I also brought the thread "vapor lock" back to life inquiring about a good brand purge valve being that i never replaced that when this issue arose years ago. Ive also looked at all my vaccum lines i could find and have dound no visible issues.

just did head gasket due to overheating issues caused by a poor electric fan setup. While the intake was off i inspected intake mani+ plenum which seems to be holding up just fine being that i did hughes repair back in 2015.
Any help appreciated.

 

P0141 O2 Sensor 1/2 Heater Failure
P0135 O2 Sensor 1/1 Heater Failure
P0138 O2 Sensor 1/2 Circuit Voltage High
You might want to check and see if you have power going to the hot wire for the heater circuit. If not the relay may be bad. The heater in the 02's help get it up to temp so the pcm gets accurate info.

 

I dont see a relay for 02 sensor. All ive seen was a 15 amp fuse for the 02 sensor. I will try an track down the hot wire

 

Jow m

How much voltage am i supposed to see from the test #12? I am getting 3.6 volts

 

I'd take "battery voltage" literally. And it appears so:
https://troubleshootmyvehicle.com/ch...-sensor-test-1

 

The ASD relay powers the 02,s coil and injectors(+ battery volts).The ASD is working because if it didn't the truck would not run. But you need to check it at the 02's while it's running. Could also be a lac of ground issue so check both.

 

following the testing procedure laid out in this link...
o2 sensor at the cat key on voltage
+26.7
-11.97
6.6 ohms (new sensor)

o2 sensor in rear key on voltage
+27.2
-11.66
5.0 ohms (old sensor)
it seems i do not have the correct voltage, it seems my wire is green with white stripe unless the orange strip faded... so i believe its safe the say i have a voltage issue? The link you sent mentioned checking the cicuit between ASD relay i will work on trying that next. I did the steps exactly how the link mentioned had set of jumpers coming directly from battery under the truck.

 

i read this procedure in the book, i am a little confused how to do it correctly though? I believe im supposed to leave the connectors attached to get an accurate reading, how would i probe the wires to get a reading from them while its connected to o2 sensors?
first thought was maybe use one of these wire taps that would allow me into the wire without causing to much damage to wire, which would require me to use 4 of these to test all wires

 

I have a buddy with a scan tool we plugged in an review live numbers from o2 sensors.
1st video got cut short. Truck ran normal in this one.

2nd video at about 6:02 is where the truck starts acting up an you can see the o2 numbers drop off

if more or different info is needed to troubleshoot im sure i can log some different data.

on another note my buddy recommend a MAF sensor making things weird, told him i only have a MAP sensor on truck.
1st test- I am getting the 4.5 volts from the signal wire (connector side) with key on.
2nd test- i get 1.6 volts idiling, when i rev the engine the book says the voltage should increase as vaccum decreases; well mine did the opposite when i revved the engine the voltage dropped to .975 volts. It never went any higher than the intial 1.6 volts. Could that have anything to do with whats going on? Or is this issue seperate?

 

Might be related, might not. If the PCM thinks the engine is getting less air, it will give it less fuel, and O2 sensor readings will fall off.... Which is pretty much what you are seeing. I don't think the MAP sensors are all that expensive....