Investigating P0121 on Your 2022 Mitsubishi Outlander
A P0121 on your 2022 Mitsubishi Outlander means the ECM has detected an irregular throttle position sensor signal. The voltage is within range but the pattern doesn't match your pedal inputs—our detective has found a clue pointing to the throttle body system.
The 2022 Outlander is a complete redesign built on the Nissan-Renault CMF-C platform, powered by a 2.5L naturally aspirated four-cylinder (181 hp) with port fuel injection and CVT. The port injection system naturally keeps the throttle body cleaner than direct-injection engines. The Outlander PHEV uses a different plug-in hybrid powertrain.
Symptoms
- Check engine light on
- Hesitation during acceleration
- Rough or hunting idle
- CVT may feel jerky at low speeds
- Throttle response feels delayed
Causes Ranked
- Carbon buildup on throttle body – Even with port injection, PCV vapors deposit carbon over time. Likelihood: 40%
- Throttle body assembly issue – Internal TPS or motor wear. Likelihood: 25%
- ECM software update – First-year redesign; Mitsubishi has released calibrations for the new Outlander. Likelihood: 20%
- Wiring or connector corrosion – Heat and environmental exposure. Likelihood: 10%
- Intake air leak – Loose intake duct or gasket. Likelihood: 5%
Repair Costs
- Throttle body cleaning: $80–$150 (shop) / $10–$20 (DIY)
- Throttle body replacement: $250–$450 parts and labor
- ECM update: $80–$150 (dealer)
- Wiring repair: $100–$200
Mitsubishi's Outstanding Warranty
Your 2022 Outlander is within Mitsubishi's 5-year/60,000-mile basic warranty and 10-year/100,000-mile powertrain warranty—among the best in the industry. All P0121 repairs should be covered at no cost. The dealer uses Mitsubishi MUT-III for diagnostics.
How AutoDetective AI Can Help
Upload your Outlander's scan data to AutoDetective for a free AI diagnosis specific to the 2.5L platform.