Hey fellas! I’m absolutely stumped. I have a 2017 dodge ram 3500 6.4L that is running like poop.

Just hit 120k miles.

Originally started having problems in July of last year, around 114,000 miles. Occasionally the check engine light would come on and briefly go off, sometimes it would stay on long enough for me to jot down the codes. Took it to a couple different shops and of course each time CEL was off, and they reported back that everything seemed okay and they couldn’t find anything.

By December, it has gotten substantially worse and I finally had some free time to dive in. Two of the coils were not functioning properly, so I replaced.

Parts replaced so far haha

All Spark Plugs
All coils
Fuel Pump
Gas Cap
PCV Valve
MAP Sensor
VVT Sensor
camshaft position sensor
02 sensors
Intake Manifold gaskets
Passenger side exhaust manifold (cracked/warped)
cleaned throttle body

None of which have fixed the problem, and I have been unable to identify any vacuum leaks, but I recently noticed a bad exhaust manifold leak on the driver side.

Battery is good
Fuses are good
MDS does not seem to be stuck on

Symptoms:

Lack of power, rough idling, sometimes hard time starting, horrible mpg, hesitation, surging.

CEL codes have been all over the place recently.

Constant each time the CEL comes on is P0171 and P0174,

but sometimes accompanied by P0456, P0138, P0151PD, P0152, P0158, P1621, P1622, P0442, P0300PD

I’m slowly losing my mind and about ready to launch this thing off a cliff haha

Before this started happening, I absolutely loved this truck! Just want it to be how it is was. Has anyone else dealt with something like this?

TIA for any help, tips, advice!

 

P0171 System too lean. bank 1
P0174 System too lean bank 2
P0456 small evap leak.
P0138 O2 sensor circuit high. bank 1 sensor 2
P0151 O2 sensor circuit low, bank 2 sensor 1
P0152 O2 Sensor Circuit High Voltage (Bank 2 Sensor 1) Ok, that's confusing.....
P0442 Evap, another small leak code.
P0300 Random misfires.

The lean condition Will give you a lot of those symptoms. Why you are getting every O2 sensor code under the sun is beyond me. Think I would clear codes, run it for a bit, and see what happens.

My question would be, does it run good at first, and then within a couple minutes, starts running terrible? Or does it just run terrible right away?
What brand O2 sensors did you install?
I might be tempted to unplug ALL the O2 sensors, and see how the engine runs.

 

Replacing all the 02 sensors was essentially just a random screw it decision haha.

All those parts I listed were not replaced in one go. Each time I replaced one part at a time, cleared codes, and waited until it came back before attempting something else.

Each time something was replaced, it seems like the truck ran worse and worse, appearing to highlight whatever the actual issue may be. The truck does not run better or worse the longer it runs. It is consistently under powered and rough running from start up to shut down.

 

Verify fuel pressure..... Is your fuel system a return style??