P0420 on Your 2024 Acura Integra: What's Going On
A P0420 code on your 2024 Acura Integra means the ECM has detected reduced catalytic converter efficiency. The 2024 Integra uses a 1.5L VTEC turbocharged four-cylinder engine producing 200 horsepower in standard form, or a 2.0L VTEC turbocharged four-cylinder producing 320 horsepower in the Type S. Both are inline-four engines with a single exhaust bank. On a vehicle this new, warranty coverage makes this a painless repair.
Symptoms
- Check engine light on — Main indicator
- Normal driving feel — Performance unaffected
- Slight MPG change — Barely noticeable
- Possible sulfur smell — Faint exhaust odor
- Emissions failure — In testing states
Likely Causes
1. Software Calibration
PCM software updates from Honda/Acura that refine catalyst monitoring thresholds are a common fix for P0420 on newer vehicles. The 2024 Integra, especially the Type S with its new 2.0L turbo engine, may benefit from updated calibration data.
2. O2 Sensor Defect
A factory-defective downstream O2 sensor triggers false P0420 readings. The turbocharged exhaust environment is demanding on sensors, and defects can show up early. The Type S's 2.0L turbo produces even higher exhaust temperatures than the standard 1.5L.
3. Catalytic Converter Issue
Manufacturing defects in the close-coupled catalytic converter can cause early underperformance. The turbo engines' close-coupled converter design means any deficiency in catalyst coating is exposed quickly by the extreme operating temperatures.
4. Exhaust Connection Problem
A loose gasket or improperly sealed connection at the turbo outlet, downpipe, or converter can create a small leak. This leak introduces false air near the O2 sensor and triggers the code.
What to Do
- Take it to your Acura dealer — This is a warranty repair.
- Ask about TSBs — Software updates may be available.
- Document everything — Keep records for your service history.
- Keep driving — No restrictions needed.
Cost (If Out of Warranty)
- Software update: $0 under warranty ($100 – $150 otherwise)
- O2 sensor: $0 under warranty ($120 – $280 otherwise)
- Catalytic converter: $0 under warranty ($900 – $2,000 otherwise)
- Exhaust repair: $0 under warranty ($100 – $350 otherwise)
Safe to Drive?
Completely safe. Your 2024 Integra's safety systems, handling, and performance are unaffected by P0420. Continue enjoying the car while scheduling a warranty appointment.
Prevention
- Use premium fuel — Both engines benefit from high-octane gasoline
- Follow maintenance alerts — Acura's maintenance minder guides service timing
- Address all codes quickly — Prevent secondary converter damage
- Warm up before hard driving — Especially important for the Type S