2020 Ford F-350 Super Duty: Engine revs at slow speeds
Common wear/failure (not a recall)
Symptoms
Owners of the 2020 F-350 Super Duty report: engine revs at slow speeds. CarComplaints.com lists 1 owner complaints, average mileage 1,650 miles.
NHTSA has 14 owner complaints for the 2020 F-350 Super Duty in this area. Examples:
- NHTSA complaint ODI #11739265 (filed 05/21/2026): “The contact owns a 2020 ford f-350. the contact stated while driving at an undisclosed speed, he had a loss of motive power and check engine warning light was illuminated when driving, almost causing an accident due to not being able to accelerate. the vehicle…”
- NHTSA complaint ODI #11736551 (filed 05/08/2026): “The component/system that failed or malfunctioned is the scr (selective catalytic reduction) nox catalyst efficiency system, triggering dtc p20ee – scr nox catalyst efficiency below threshold (bank 1). this issue began immediately after ford recall 24s78 (pcm …”
Likely causes
Sources do not establish a single root cause; diagnosis is needed. Owner-reported fixes are listed below.
Fix, in plain English
Most common owner-reported solutions on CarComplaints.com: none clearly reported. Check for open recalls and extended warranty coverage with a dealer before paying out of pocket.
DIY difficulty: Pro
Internal engine work (lifters, oil consumption, fuel dilution diagnosis) requires engine teardown or dealer software/tests. (Our assessment.)
Cost
No sourced cost range: get a written quote after diagnosis.
Typical parts (search links, no affiliate codes)
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