Understanding the P0420 Code on Your 2022 Dodge Challenger
Your 2022 Dodge Challenger's check engine light just came on with a P0420 code, and you're wondering what's going on under that long hood. This code means the PCM has determined that the Bank 1 catalytic converter isn't cleaning up exhaust emissions as efficiently as it should. The 2022 Challenger is powered by either the 3.6L Pentastar V6 (303 hp in SXT trim), the 5.7L HEMI V8 (375 hp in R/T), the 6.4L HEMI V8 (485 hp in Scat Pack), or the supercharged 6.2L HEMI in Hellcat models. Bank 1 is the passenger side cylinder bank on the V8 engines.
Since the 2022 model is still fairly new, there's a decent chance this isn't a fully worn-out converter. Let's dig into the most likely causes.
What Symptoms Might You Notice?
- Check engine light illuminated — Almost always the first thing you'll see
- Slightly worse gas mileage — Possibly 1-2 MPG less than normal
- Egg-like sulfur smell — Coming from the tailpipe area
- Normal driving feel — Most owners report no change in performance
- Emissions inspection failure — In states that require testing
Common Causes for the 2022 Challenger
1. Faulty Downstream O2 Sensor
On a vehicle with only a few years of age, the downstream oxygen sensor is a top suspect. The Bank 1 Sensor 2 monitors the converter's efficiency, and if it has become sluggish or contaminated, it'll generate a false P0420. Sensor failure is more common than converter failure on newer vehicles like the 2022 Challenger.
2. Catalytic Converter Manufacturing Defect
While less common, a defective catalytic converter from the factory isn't unheard of. The internal catalyst substrate may have been improperly coated or could have suffered damage during assembly. Since the 2022 should still be under warranty, this would be covered at no cost to you.
3. Exhaust System Leak
A leak in the exhaust system upstream of the downstream O2 sensor allows fresh air to contact the sensor, skewing its readings. Common leak points on the Challenger include the exhaust manifold gaskets, catalytic converter inlet flange, and welded joints. Road vibration and thermal cycling can open up small leaks over time.
4. ECM Software Calibration
Chrysler periodically releases updated PCM software that adjusts the sensitivity of the catalyst monitoring system. Your 2022 Challenger may need a software flash to recalibrate the converter efficiency thresholds. Check with your dealer for any applicable TSBs.
Diagnostic Steps
- Check for companion codes — Additional codes alongside P0420 can significantly narrow down the root cause.
- Review O2 sensor live data — Compare Bank 1 upstream and downstream sensor waveforms. The downstream should be stable when the converter is healthy.
- Inspect exhaust connections — Check all gaskets, flanges, and welds from the exhaust manifold to the downstream sensor location.
- Verify with your dealer — Ask about any TSBs or software updates for the 2022 Challenger's emissions system.
What Will Repairs Cost?
- Catalytic converter replacement: $1,100 – $2,600 (likely warranty-covered on a 2022)
- Downstream O2 sensor: $125 – $290 including parts and labor
- Exhaust leak repair: $100 – $400 depending on the leak location
- PCM software update: $0 – $150 (may be free under TSB coverage)
Is It Safe to Keep Driving?
Yes. A P0420 code on your 2022 Challenger is not a safety concern and won't damage your engine in the short term. The car will drive perfectly normally. Since your vehicle is likely still under the factory warranty and federal emissions warranty (8 years/80,000 miles for converters), schedule a dealer visit sooner rather than later for a potentially free repair.
Prevention Tips
- Don't ignore misfires — Fix any rough running or misfire codes immediately to protect the converter
- Use quality fuel — Top Tier gasoline and the correct octane rating for your engine
- Keep up with scheduled maintenance — Oil changes, spark plugs, and air filters on schedule
- Let the engine warm up properly — Especially important during cold weather before hard driving