Given the (lack of) quality of some of the aftermarket parts..... I wouldn't be surprised at just about any failure mode. I am actually surprised when they work the way they are supposed to.

 

Honestly, this is the first time I've ran into this issue... and I've always put the cheapest stuff I can find on my beaters... but maybe I've just got lucky and it's finally ran out... haha!

Got the SMP in today - a day early!
Went out and plugged it in - 4.6v on signal return...
fired it up - ran poorly still... 2.2v on return...


Ignore the dirty shop... been working on clearing out all the clutter that was left behind bay by bay and from the doors to the back 😂

Anyway -
​​​​​​Swapped for original PCM for fun.
ran a hint better...? 1.7-1.9v on return signal...
Got live data to work this time and showed the 40s for MAP reading.


Ran the truck for at least 5 if not 10minutes - no codes.
​​​​​​Still running rich. Hesitation on the pedal and backfiring when letting off. Definitely rich but no where near as bad as what it was! Or seems better...?

Aren't these readings going sort of the opposite of what they're supposed to be though...?

 

Idle around 800 or so? If that's the case, map is actually reading correct. Should be seeing 18 to 20 inches of vacuum on the manifold.

What do the other sensors have to say for themselves? Engine temp? TPS?

 

Only took 3 new MAP sensors to get there too! 😂

I'll get back out there tomorrow after work and get readings on the the TPS and... ECT/coolant sensor...? The one by the thermostat housing?

Anything else you'd like me to look at while she's running?

​​​​​I feel like I could think of things to check but this truck has me feeling stupid... haha!

 

Basically wanna look at anything that would influence fueling. So, engine temp, throttle position, intake air temp, etc. O2 sensors won't play role for the first couple minutes of run time.....

 

I'm hoping that the engine temp should be fine - brand new sensor and it was reading accurately after I replaced it - but we will see!
I'll definitely see if I can get live data to work again after work and see what we can find out...

Out of curiosity I decided to look up the TPS, IAC, IAT sensors to see about their availability and AMAZINGLY all three of those are IN STOCK (supposedly) at the parts store closest to me! ... About 3x the price of what you could buy them online for but still... And here I was just complaining about how you cant get anything for these trucks in the part store... Haha!

 

For critical sensors, crank/cam position, and IAC motor, you REALLY want genuine mopar sensors there. They actually work properly. The aftermarket sensors don't seem to be as friendly with our trucks, and can lead to 'mystery' issues.

 

Well, dang... But I suppose that makes sense. I'll have to keep that in mind for the future though. Hopefully won't need to! Haha!

 

I agree TPS and ECT would be good to know. Either could cause fueling issues and throttle hesitation. As HeyYou said, O2 sensors can also cause this but wouldn't come into play at cold idle.

I guess worst case you could have a leaky injector(s), but I wouldn't go down that rabbit hole just yet. Also wonder if it maintains fuel pressure after being shut off (although this could also be a problem at the pump)?

 

Just out of curiosity have you checked to see if the ground straps are attached to the back of the cylinder heads? Also have you checked plugs yet? What do they look like, is there a particular cylinder that seems off? I would pull all the plugs, it may give us some things to narrow down. Why were the heads reworked?