P0420 on CHEVROLET CRUZE — Catalyst System Efficiency Below Threshold Bank 1

Q: "What does P0420 mean on a CHEVROLET CRUZE?"

"P0420 indicates: Catalyst System Efficiency Below Threshold Bank 1. This is a emission controls code. 7 CHEVROLET CRUZE owners have reported this to NHTSA."

Q: "What are the most common causes of P0420 on CHEVROLET CRUZE?"

"Based on 7 NHTSA reports, the most commonly cited components are: Engine, Fuel/Propulsion System, Power Train,Engine. These percentages are based on the component field in owner complaints."

Q: "Is P0420 serious on my CHEVROLET CRUZE?"

"Of 7 NHTSA reports for this code on CHEVROLET CRUZE, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic."

Q: "What should I do if my CHEVROLET CRUZE shows P0420?"

"1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare."

What P0420 Means on Your CHEVROLET CRUZE

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.

7 CHEVROLET CRUZE owners have reported this issue to NHTSA across model years 2014-2016. Most reports come from the 2014, 2015 model years. The most commonly reported component is Engine (42.9% of reports).

Real CHEVROLET CRUZE Owner Reports

Source: NHTSA Complaints Database

"Vehicle has a faulty catalytic converters had the check engine light on got it tested the p0420 code issued."

— 2014 CHEVROLET CRUZE owner · FUEL/PROPULSION SYSTEM · Filed 05/18/2022

"I took my car into King Chevrolet last year around August. The car was overheating and the fan was running almost all the time. When they ran the diagnoses which I was charged 100 dollars for, they told me I had a loose plug. About 1 month after that, it started doing it again."

— 2014 CHEVROLET CRUZE owner · ENGINE · Filed 08/05/2021

"I have a code p0420 code and engine light keeps comeback on I had the catalytic converter replaced, and everything inspected by Friendship Chevrolet in Forestcity NC 28043. Kept my car for two weeks and still couldn’t find the problem of this p0420 code so my engine light stays on."

— 2014 CHEVROLET CRUZE owner · POWER TRAIN,ENGINE · Filed 09/22/2021

"I am have issues with the p0420 error code. i took the car to a mechanic who advised that the catalytic converter needed to be replaced. not believing what he said due to the car being fairly new. i went to auto zone to have the codes read and of course the code displays with the p0420 code."

— 2014 CHEVROLET CRUZE owner · FUEL/PROPULSION SYSTEM · Filed 05/22/2020

"Engine light came on at about 107000 miles. diagnosed as code p0420 catalytic converter efficiency low. replaced with aftermarket catalytic converter made by walker, but code did not clear. contacted gm customer care, was sent to elkins chevrolet."

— 2014 CHEVROLET CRUZE owner · ENGINE · Filed 06/19/2019

All reports filed by vehicle owners directly with the U.S. Department of Transportation.

📊 Complaint Trend by Model Year

5

'14

1

'15

1

'16

Common Causes on CHEVROLET CRUZE

Based on NHTSA complaint component analysis for this vehicle.

ENGINE 42.9%

FUEL/PROPULSION SYSTEM 28.6%

POWER TRAIN,ENGINE 14.3%

ENGINE,FUEL/PROPULSION SYSTEM 14.3%

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.

Frequently Asked Questions

What does P0420 mean on a CHEVROLET CRUZE? ▾

P0420 indicates: Catalyst System Efficiency Below Threshold Bank 1. This is a emission controls code. 7 CHEVROLET CRUZE owners have reported this to NHTSA.

What are the most common causes of P0420 on CHEVROLET CRUZE? ▾

Based on 7 NHTSA reports, the most commonly cited components are: Engine, Fuel/Propulsion System, Power Train,Engine. These percentages are based on the component field in owner complaints.

Is P0420 serious on my CHEVROLET CRUZE? ▾

Of 7 NHTSA reports for this code on CHEVROLET CRUZE, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic.

What should I do if my CHEVROLET CRUZE shows P0420? ▾

1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare.