Why does my Kia Carnival hesitate when I accelerate?

Short answer: Carnival hesitation can be the 3.5 V6 fuel injectors and piping (Kia has a bulletin with air-fuel imbalance codes like P219C) or transmission learning. Check for open fuel recalls first.

Symptom: A lag or stumble when you press the gas, odd shifting at low speed, a check-engine light with reduced power, or the engine shutting off.

What to check first

1. Run your VIN at nhtsa.gov/recalls for the fuel rail and fuel pipe recalls.
2. If the check-engine light is on, get the codes read. Imbalance codes like P219C point to the fuel bulletin.
3. Tell the dealer exactly when it hesitates (from a stop, merging, warm or cold).
4. If it shuts off while driving, stop driving it and have it towed in.

Likely causes

1. 3.5 V6 fuel injector / fuel piping issue. Kia issued a bulletin for 3.5L Lambda III engines with reduced power and cylinder air-fuel imbalance codes (like P219C). The fix involves high-pressure injectors and fuel piping.
2. Transmission adaptive values or software. Some shift hiccups may be the transmission's learned values or software. Ask the dealer to check for updates before replacing parts.
3. Fuel rail or fuel pipe recall. NHTSA lists Carnival recalls for a damaged plastic fuel rail tube and fuel leaking at the fuel pipe to rail connection. Check your VIN.

What it usually costs

Recalls are free, and bulletin repairs are warranty items on newer vans. Out of warranty, injector and fuel piping work is a mid-size to large repair.

Is it safe to keep driving?

Mild hesitation can be driven to the dealer. A fuel smell or the engine shutting off is not safe. Stop and tow it.

DIY or shop?

Not DIY. Fuel system and software work belong at the dealer.

Recalls, bulletins and complaints in plain words

• Related recalls: NHTSA lists these recalls touching this area of the Kia Carnival: 21V277000 (2022-2022 model years, fuel system, gasoline:fuel injection system:fuel rail); 26V232000 (2022-2024 model years, fuel system, gasoline:delivery:hoses, lines/piping, and fittings). Check your VIN at nhtsa.gov/recalls. If your car is part of this recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect.
• NHTSA complaints: 60 keyword-matched complaints for Kia Carnival 2022–2024 (of 266 unique complaints queried, NHTSA complaints API by model year, queried 2026-11-07; keywords: hesitat, transmission, shift, accelerat, stall, power). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In 2023 Carnival having hesitation on acceleration? on Reddit r/kiacarnivals, a 2023 Carnival owner asked whether others feel hesitation when accelerating.
• In Transmission shifting first-second then first again. on Reddit r/kiacarnivals, an owner said the van shifts from first to second and then back to first again.
• In 2022 Carnival: Engine Shutting Down Again — Probably the End for Us and Our Carnival on Reddit r/kiacarnivals, a 2022 Carnival owner said the engine kept shutting down while driving and they were ready to give up on the van.

Quick tip

Fuel recall first, then codes. Don't let anyone reset the computer before they've read and written down the codes.

Vehicle focus: Kia Carnival (2022–2024) with the 3.5L V6 and 8-speed automatic.

Safety / mechanic note

A fuel leak or stall in traffic is a serious hazard. Verify with a mechanic.