2021 Hyundai Tucson: Dangerous delay in acceleration
Common wear/failure (not a recall)
Symptoms
Owners of the 2021 Tucson report: dangerous delay in acceleration. CarComplaints.com lists 1 owner complaints, average mileage 4,000 miles.
NHTSA has 8 owner complaints for the 2021 Tucson in this area. Examples:
- NHTSA complaint ODI #11758305 (filed 08/20/2026): “See attached document for complaint.…”
- NHTSA complaint ODI #11716729 (filed 02/09/2026): “The vehicle experienced a catalytic converter efficiency failure that was confirmed by an authorized dealership in january 2025. the dealer indicated the catalytic converter required replacement; however, the replacement was not performed, and the vehicle was …”
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
Diagnosis needs a scan tool; repair or replacement needs a lift, transmission jack and the manufacturer's fluid fill/relearn procedure. (Our assessment.)
Cost
No sourced cost range: get a written quote after diagnosis.
Typical parts (search links, no affiliate codes)
AutoZone · O'Reilly · Advance · RockAuto
Sources
Page last updated .