P0420 Code on Your 2023 Dodge Charger: What You Need to Know
Seeing a P0420 code on your 2023 Dodge Charger can be concerning, especially on a relatively new vehicle. This code indicates that the Bank 1 catalytic converter is not performing at the expected efficiency level. The 2023 Charger — one of the final years of the iconic muscle car's current generation — is available with the 3.6L Pentastar V6 (292 hp), 5.7L HEMI V8 (370 hp), or the 6.4L HEMI V8 (485 hp) in R/T Scat Pack trim. Understanding your specific engine helps narrow down the diagnosis.
Since the 2023 model year is still quite new, a P0420 code often points to something other than a completely worn-out converter. Let's investigate what might be going on.
Symptoms You Might Notice
- Check engine light on — The most obvious and often only symptom
- Slight decrease in gas mileage — May not be immediately noticeable
- Faint sulfur smell from the tailpipe — Indicates the converter is struggling
- No performance changes — In most cases, drivability remains normal
- Failed emissions inspection — If your state requires testing
Why Your 2023 Charger Is Showing P0420
1. Downstream O2 Sensor Issue
On a vehicle this new, a faulty downstream oxygen sensor is actually one of the more likely causes. The Bank 1 Sensor 2 O2 sensor monitors the catalytic converter's output. A sensor that's reading incorrectly — perhaps due to contamination or an electrical issue — can trigger a false P0420 code. This is the best-case scenario because it's the cheapest fix.
2. Software or Calibration Issue
Some 2023 Chargers may have PCM calibration issues that set the P0420 code prematurely. Chrysler occasionally releases software updates through Technical Service Bulletins (TSBs) that adjust the catalyst monitoring thresholds. Your dealer can check for available updates.
3. Catalytic Converter Defect
While uncommon on a new vehicle, manufacturing defects in the catalytic converter can cause early failure. Improperly coated substrate or internal damage during assembly can reduce converter efficiency from the start. This would be a warranty repair.
4. Exhaust Leak
A small exhaust leak near the converter or downstream sensor can introduce false air into the reading. Loose connections, cracked welds, or a faulty gasket between the exhaust manifold and converter are all possibilities worth checking.
Diagnosis Process
- Check for TSBs and recalls — Have your dealer scan for any software updates related to emissions or catalyst monitoring for the 2023 Charger.
- Scan all stored and pending codes — Additional codes alongside P0420 narrow the diagnosis significantly.
- Monitor O2 sensor live data — Compare Bank 1 upstream and downstream sensor waveforms. The downstream should be nearly flat on a healthy converter.
- Inspect exhaust system — Look for leaks, loose hardware, or damage from road debris.
- Check for warranty coverage — The 2023 model should still be under both the factory powertrain warranty and the federal emissions warranty.
Repair Costs
- Catalytic converter replacement: $1,100 – $2,500 (likely covered under warranty for a 2023 model)
- Downstream O2 sensor: $130 – $280 for parts and labor
- PCM software update: $0 – $150 (free if covered by a TSB, diagnostic fee may apply)
- Exhaust leak repair: $100 – $350 depending on the location
Is It Safe to Drive Your Charger?
Absolutely. A P0420 code does not affect the safety or basic drivability of your 2023 Charger. You can continue driving it normally while you schedule an appointment. However, since the vehicle is still likely under warranty, there's no reason to delay getting it checked — the repair may not cost you anything.
Prevention Tips
- Use quality fuel — Premium is recommended for HEMI engines and helps keep the entire fuel system clean
- Don't ignore other engine codes — Misfires and fuel system problems are catalytic converter killers
- Keep up with maintenance — Follow the maintenance schedule in your owner's manual
- Let the engine warm up — Avoid aggressive driving until the engine reaches operating temperature