P0131 on Your 2020 Dodge Charger: What It Means
When your 2020 Dodge Charger throws a P0131, the ECM is telling you that the Bank 1 Sensor 1 oxygen sensor is producing a voltage below 0.2V for an extended period. The 2020 Charger comes in multiple engine configurations — the 3.6L Pentastar V6, the 5.7L HEMI V8, the 6.4L HEMI V8 (Scat Pack), or the supercharged 6.2L HEMI (Hellcat). On all V-configuration engines, Bank 1 is the driver's side (left side), and Sensor 1 is the upstream sensor ahead of the catalytic converter. On HEMI V8 models, remember that there are dual sensor banks — Bank 1 and Bank 2 each have their own upstream and downstream sensors.
Common Symptoms
- Check engine light illuminated
- Reduced fuel economy, especially noticeable on the V8 models
- Subtle rough idle or minor misfires at low RPM
- Slight hesitation during acceleration from a stop
- May notice exhaust smell if running overly rich on Bank 1
What Causes P0131 on the Charger
1. Failed Upstream O2 Sensor
On the HEMI V8 engines, the upstream O2 sensors endure extreme heat from the cast iron exhaust manifolds. The 5.7L and 6.4L HEMIs are known for running hot, and the Bank 1 Sensor 1 sits right at the driver-side manifold outlet. Over time, the sensor's internal element loses sensitivity and locks into a low-voltage reading. With the 2020 model having several years and potentially 50,000+ miles, sensor degradation is the most common culprit.
2. Wiring Harness Damage
The Charger's O2 sensor harness routes along the driver's side of the engine, near the exhaust manifold and heat shields. Heat damage to wire insulation, rodent chewing, or connector corrosion from road salt exposure can create high resistance on the signal wire, pulling voltage low. The HEMI's robust exhaust heat makes this wiring particularly vulnerable.
3. Exhaust Manifold Leak
The HEMI V8 exhaust manifolds are well-known for developing cracks or warping at the manifold-to-head gasket. A leak on the Bank 1 side allows ambient air to reach the O2 sensor, causing a false lean reading. Listen for a ticking noise at cold start that fades as the engine warms — this is the classic manifold leak signature on HEMI engines.
4. Lean Fuel Condition
If the Charger is genuinely running lean on Bank 1, the O2 sensor is simply reporting what it sees. Vacuum leaks at the intake manifold gasket, a weak fuel pump (especially on high-horsepower variants), or a clogged injector can all cause a true lean condition. Look for P0171 stored alongside P0131 as confirmation.
Diagnostic Steps for the Charger
- Use a scan tool to monitor Bank 1 Sensor 1 voltage in real time. A working sensor should cycle between 0.1V and 0.9V.
- Compare Bank 1 and Bank 2 sensor readings side by side — if Bank 2 is cycling normally and Bank 1 is stuck low, the problem is isolated to Bank 1.
- Inspect the driver-side exhaust manifold for cracks and the manifold bolts for looseness.
- Check the sensor connector and wiring for heat damage or corrosion.
- Review fuel trims — Bank 1 LTFT above +15% with Bank 2 normal suggests a Bank 1-specific lean issue.
- If isolated to the sensor, replace with an OE Mopar-spec unit.
Repair Costs
An OE-spec upstream O2 sensor for the 2020 Charger HEMI costs $70–$180. Labor runs $100–$200 at a shop. Total: $170–$380. If the exhaust manifold is cracked (common on HEMIs), repair costs jump to $400–$900 including the manifold and gaskets. DIY sensor replacement is moderate difficulty — the sensor is accessible but may require penetrating oil and patience if it's seized from heat.
Urgency Level
This is a moderate-priority repair. Your Charger won't leave you stranded, but the performance-oriented HEMI engines rely on precise air-fuel ratios. Driving with P0131 reduces power, wastes fuel, and can damage the Bank 1 catalytic converter over time.