P0420 on Jeep Compass
Catalyst System Efficiency Below Threshold Bank 1
Methodology: Reviewed against the SAE J2012 generic DTC definition and NHTSA owner-complaint patterns, then scoped to Jeep Compass 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 Jeep Compass
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 Jeep Compass Owner Reports
Source: NHTSA Complaints Database
"Every time i fill my jeep up with gas not even 5 secs after i leave the engine turns off. now the check engine has popped up on my dashboard. i ran a code reader and it found code p0420."
"We have been receiving a check engine light on our 2012 Jeep Compass for code P0420. Reset the system but subsequently vehicle failed emissions testing. After some research we discovered this model vehicle and several others were supposed to be receiving a recall of the catalytic converters."
"The contact owns a 2015 Jeep Compass. The contact stated that while driving at an undisclosed speed, the check engine warning light was illuminated. Additionally, while coming to a complete stop, the accelerator pedal was depressed; however, the vehicle failed to accelerate immediately."
"The contact owns a 2016 Jeep Compass. The contact stated while driving 60 MPH, the check engine warning light illuminated. While driving uphill, the vehicle was chugging. The vehicle was difficult to shift into gear."
All reports filed by vehicle owners directly with the U.S. Department of Transportation.
📊 Complaint Trend by Model Year
Common Causes on Jeep Compass
Based on NHTSA complaint component analysis for this vehicle.
What To Do Next
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1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
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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.
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3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.