P0420 on Nissan Pathfinder
Catalyst System Efficiency Below Threshold Bank 1
Methodology: Reviewed against the SAE J2012 generic DTC definition and NHTSA owner-complaint patterns, then scoped to Nissan Pathfinder context without treating complaints as confirmed diagnoses.
Sources: SAE/OBD-II definitions, manufacturer service information, and public reliability reports (including NHTSA where applicable).
- SAE J2012 Diagnostic Trouble Code Definitions — Generic diagnostic trouble code definition reference for P0420.
- NHTSA recalls, complaints, and manufacturer communications — Used to check public owner complaint context, recall status, and safety-related manufacturer communications by VIN or vehicle.
Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.
What P0420 Means on Your Nissan Pathfinder
P0420 is a diagnostic trouble code indicating: Catalyst System Efficiency Below Threshold Bank 1. This code relates to the emission controls system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
Real Nissan Pathfinder Owner Reports
Source: NHTSA Complaints Database
"[fuel level sensor] service engine light went on august 10, 2008, two codes p0463(fuel level sensor) and p0420(catalytic efficiency low). shortly after this; when filling-up the fuel gauge would read "e" after some time it would read correctly. this problem is intermittent."
"Cvt transmission problem : (1) the codes that were stored were p01710 cvt judder code & p0420 trans fluid low code (2) and transmission is taking 10secs to shift properly so needs a new transmission."
All reports filed by vehicle owners directly with the U.S. Department of Transportation.
📊 Complaint Trend by Model Year
Common Causes on Nissan Pathfinder
Based on NHTSA complaint component analysis for this vehicle.
What To Do Next
-
1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
-
2
Get a proper diagnosis
A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50–$150) pinpoints the root cause before you spend money on parts.
-
3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.