✅ Fixed
Downstream O2 sensor replaced first $85. Code returned 1000 miles later. Catalytic converter genuinely worn — replaced with quality aftermarket $320. Passed emissions test.
Dodge Ram 1500 2021 Catalytic converter P0420 code
2021
P0420
On This Page:
🔍 Symptoms
⚙️ Causes
🔧 All Repairs
⚠️ Avoid These
🧾 Driver Reports
🔗 Similar Faults
🩺 Related Symptoms
⚡ Quick Summary
Severity Level
Medium
Safe to Drive?
⚠️ Drive with Caution
Safety Impact
Indirect risk — worth monitoring, not urgent
Urgency Level
🟡 Monitor Closely
Dodge Ram 1500 2021 P0420 catalytic converter efficiency below threshold. Car runs fine. Failed emissions test. 53172 km. This fault code is stored when the engine control unit detects a specific fault condition. Common causes include sensor failures, wiring faults, and component wear. Always read additional fault codes before replacing parts — multiple codes together provide a clearer diagnosis. Clear the code after repair and test drive to confirm the fault does not return.
🔍 Symptoms
📍 Catalytic converter — P0420 code
📍 Dodge Ram 1500
⚠️ P0420 fault code
⚙️ Possible Causes
Fault code P0420 detected
Catalytic converter — P0420 code
Dodge Ram 1500
Possible: Downstream O2 sensor replaced first $85. Code returned 1000 miles later. Catalytic converter genuinely worn — replaced with quality aftermarket $320. Passed emissions test.
Repair / Solution
Based on 140 driver confirmations
⚠️ Wrong Diagnosis?
No commonly reported misdiagnoses for this fault yet. If you have replaced a part that did not fix this 2021 problem, submit a wrong diagnosis report — it helps other drivers avoid the same costly mistake.
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