CHEVY K1500 SERVICE ENGINE LIGHT IS ON DUE TO P0420

1998 Chevrolet Silverado

Tiny

usmc91187

December, 6, 2010 AT 5:49 PM

How can I tell if my O2 sensors or cady converter need to be replaced. I can hear a raddling noice underneath somwhere while driving and it is burning rich. Other than that truck is running great.

FOUND 17085 RELATED QUESTIONS

1 Answer

Tiny

rasmataz

December, 6, 2010 AT 5:54 PM

A code P0420 may mean that one or more of the following has happened: Leaded fuel was used where unleaded was called for
An oxygen sensor is not reading (functioning) properly
The engine coolant temperature sensor is not working properly
Damaged or leaking exhaust manifold / catalytic converter / exhaust pipe
Retarded spark timing
The oxygen sensors in front and behind the converter are reporting too similar of readings
Possible Solutions Some suggested steps for troubleshooting a P0420 error code include: Check for exhaust leaks at the manifold, pipes, catalytic converter. Repair as required.
Use a scope to diagnose the oxygen sensor operation (Tip: The oxygen sensor in front of the catalytic converter normally has a fluctuating waveform. The waveform of the sensor behind the converter should be more steady).
Inspect the downstream heated oxygen sensor (HO2), replace if necessary
Replace the catalytic converter

Please login or register to post a reply.

Code Read Retrieval/Clear Scion XD
How to read codes Chevrolet Blazer
Read Codes Like a Pro
 Step by Step video GMC Yukon XL 2000-2006
Code Read Retrieval/Clear
Code Read Retrieval/Clear Chevrolet Camaro