Truck "bucks" at slow, steady speeds

[Doc]

$30 install is cheap...I'd paid someone that to have it done...for a seniors, it's a bit of PIA to reach where it's located...

I just let the clutch out smoothly ..

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[Msfitoy]

I just let the clutch out smoothly ..

You found the clutch pedal?!

 

[AzScorpion]

I need a thirty dollar mechanic.

Here's one and he works for for bananas. ?

 

[Doc]

You found the clutch pedal?!

Glove Compartment ..

 

[IdahoRanger]

Here's one and he works for for bananas. ?

Yeah, a $30 mechanic is probably as good as a $30 wh***.

 

[Chris M]

Yeah, a $30 mechanic is probably as good as a $30 wh***.

Yeah.
Either way you're screwed and unlikely to recover from it.

 

[ExtendedWarrantyWinner]

Replaced the whole EGR sensor/hose component last week and still feels like there's some jerky surging while trying to cruise around town in the 30mph 7th gear 1,200-1,300 rpm range. Overall it's much better and feels like it knows how to shift again without having to put the pedal through the carpet on inclines but it's definitely still far from what I would think a drivetrain made after 1923 should drive like.

Anyone else have the issue not completely go away after swapping the sensor? Any other ideas to help this go away?

 

[notsolinear]

Replaced the whole EGR sensor/hose component last week and still feels like there's some jerky surging while trying to cruise around town in the 30mph 7th gear 1,200-1,300 rpm range. Overall it's much better and feels like it knows how to shift again without having to put the pedal through the carpet on inclines but it's definitely still far from what I would think a drivetrain made after 1923 should drive like.

Anyone else have the issue not completely go away after swapping the sensor? Any other ideas to help this go away?

Yes, that sounds pretty much identical to my experience. On the extremely rare chance my replacement sensor was also bad I bought a second from another vendor, same result. What I never was able to do is hook up to a scan tool that would have confirmed if the differential pressure and valve position readings matched others with the issue; I continue to wonder if maybe it was something different that just happens to manifest extremely similarly.

 

[airline tech]

The other sensor that could tie into the Bucking would be the MAPT sensor, as this is also looking at manifold pressure. But you will need a Live Data view to confirm, the same as the DPFE sensor.
When EGR is flowing it affects manifold pressure, and it adjusts fuel delivery & timing.
But keep in mind that there are other sensors the PCM is looking at as well to calculate fuel delivery & timing such as the ECT and CHT.
This is why it is best to get a Live Data drive cycle and actually view the PID's to see what they are reporting.
The MAPT sensor is another sensor that SOMETIMES will not code unless it is electrically dead or way out of specs in reporting data, just like the DPFE sensor and the only way to see it is using Live Data.

It may be the case that the DPFE is now working properly and commanding the EGR valve as it should, but the MAPT sensor is not accurately seeing (reporting) the added EGR flow when the EGR vale is open, thus it is not adjusting Fuel & Timing to account for the extra flow, but it could also be another sensor (temp) falsely reporting to the MAPT or EGR Tubing clogged or another sensor in the EGR system falsely reporting data.

As you see, there are some various sensors in the system that can produce the Buck/Surge, and you can shotgun parts all day long and never find it.
This is why for this symptom we have been lucky to shotgun the DPFE and fix the issue, but if it still remains it requires a deep look at the PID data to accurately locate the issue.

 

[ExtendedWarrantyWinner]

The other sensor that could tie into the Bucking would be the MAPT sensor, as this is also looking at manifold pressure. But you will need a Live Data view to confirm, the same as the DPFE sensor.
When EGR is flowing it affects manifold pressure, and it adjusts fuel delivery & timing.
But keep in mind that there are other sensors the PCM is looking at as well to calculate fuel delivery & timing such as the ECT and CHT.
This is why it is best to get a Live Data drive cycle and actually view the PID's to see what they are reporting.
The MAPT sensor is another sensor that SOMETIMES will not code unless it is electrically dead or way out of specs in reporting data, just like the DPFE sensor and the only way to see it is using Live Data.

It may be the case that the DPFE is now working properly and commanding the EGR valve as it should, but the MAPT sensor is not accurately seeing (reporting) the added EGR flow when the EGR vale is open, thus it is not adjusting Fuel & Timing to account for the extra flow, but it could also be another sensor (temp) falsely reporting to the MAPT or EGR Tubing clogged or another sensor in the EGR system falsely reporting data.

As you see, there are some various sensors in the system that can produce the Buck/Surge, and you can shotgun parts all day long and never find it.
This is why for this symptom we have been lucky to shotgun the DPFE and fix the issue, but if it still remains it requires a deep look at the PID data to accurately locate the issue.

Is this something mere mortals can do or should I seek professional help? And by professional help I mean not a Ford dealer, they've done nothing but gaslight and know nothing about my rolling house of horrors.

I've already shotgunned the transmission and EGR sensor and while things are better I'd love to actually have some sort of idea as to what's going on.

 

[airline tech]

Is this something mere mortals can do or should I seek professional help? And by professional help I mean not a Ford dealer, they've done nothing but gaslight and know nothing about my rolling house of horrors.

I've already shotgunned the transmission and EGR sensor and while things are better I'd love to actually have some sort of idea as to what's going on.

If you are asking about the MAPT sensor - it's easier than the DPFE, you just want to be VERY CAREFUL as sometimes (due to it being plastic) the nipple can crack and break off in the intake when removing it.

Here is @Trash Pandas thread on replacement

Manifold Absolute Pressure and Temperature Sensor Replacement (MAPT) Write-Up (K2GZ-9F479-A) | 2019+ Ford Ranger and Raptor Forum (5th Generation) - Ranger5G.com

 

[ExtendedWarrantyWinner]

Great, thank you, I'll give that a go too. My truck has a similar build date so it seems reasonable to think that the sensors could wear out on a similar timeline.

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