Q: What does this code mean P0420 ? 1997 Chevy Express 1500

asked by on

Catalyst efficiency below theashold light is on what does it mean engine light is on and that what it said

My car has 234 miles.
My car's transmission is unknown to me.

Hello - the P0420 code means the catalytic converter has lost it’s ability to burn residual fuel. This could be due to an engine condition that has clogged the catalyst, or a failing oxygen sensor that is not adequately monitoring exhaust gases, and feeding bad data to engine management. The result is the same, inadequate catalytic converter functionality. I would recommend a Check Engine inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. What does this code mean P0420 ? 1997 Chevy Express 1500

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: What can cause the RPMs to go super high while driving at one constant speed?

Hi There, It sounds like you are describing the symptoms of a failing throttle position sensor. The throttle position sensor monitors the throttle position of the throttle plate inside the throttle body in relation to your foot position on the...

Q: Would a clogged catalytic converter burn a hole in the manifold

Hi and thanks for contacting YourMechanic. The hole in the manifold is a sign of something coming out of the engine, either a piston or a valve. If the manifold is the intake manifold, then there could be a burned...

Q: Check Engine light says replace catalytic converter

It would be helpful to know the exact code in this case. The Check Engine Light themselves do not tell us to replace components, they point us to a possible cause of a malfunction. If the code is for catalytic...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...