answersLogoWhite

0

This code is generic and is the same on all vehicles. P0420 = Catalyst System Efficiency Below ThresholdCatalyst System Efficiency Below Threshold. This means that the secondary O2 sensor detects that the catalytic converter isn't working as efficiently as it should. This engine code can be triggered by any one of the following:

1.) The catalyst in the catalytic converter is cracked, clogged, or otherwise damaged.

2.) The secondary O2 sensor is malfunctioning.

3.) There is an exhaust leak.

4.) The computer unit is faulty

User Avatar

Wiki User

17y ago

Still curious? Ask our experts.

Chat with our AI personalities

ReneRene
Change my mind. I dare you.
Chat with Rene
MaxineMaxine
I respect you enough to keep it real.
Chat with Maxine
SteveSteve
Knowledge is a journey, you know? We'll get there.
Chat with Steve

Add your answer:

Earn +20 pts
Q: What does P0420 code mean on a 2001 Chevy Tahoe?
Write your answer...
Submit
Still have questions?
magnify glass
imp