Questions & Answers for: Buick p0420

p0420 code In case anyone else comes across this, there's a 90% chance the converter has failed. Check that the rear O2 sensor is working right using an oscilliscope or scan tool. If it's OK then the ...

2002 chevy impala p0420 code. Not really sure what this means or how to fix the problem here is a site that may help you with your po420 code http://www.aa1car.com/library/p0420_dtc.htm Probably a ...

had p0420 code on buick v-6. replaced cat. convrter, both o2 sensors and had tune up. light still comes on. A code P0420 may mean that one or more of the following has happened: Leaded fuel was used ...

check engine light on, code reads p0420 Hi and welcome to FixYa! Code p0420 means Catalyst System Efficiency Below Threshold (Bank 1). This will surely needs attention to resolve the problem. Hope ...

p0420 code what is it &how to fiw The DTC P0420 is refer to the Catalyst System Efficiency Below Threshold (Bank 1) The catalytic converter has an oxygen sensor in front and behind it. When the ...

code p0420 catalyst system low efficiency bank 1 Just did the P0430,so here's the P0420 trouble code.Trouble Code: P0420Catalyst System Bank 1 Low Efficiency Possible Causes: Air leaks at the exhaust ...

How many times does the catalytic converter test have run before the code P0420 clears. I cleaned out the catalytic converter by running sea foam through the vacuum system and it completed a cycle ...

check the meaning of codes, for p0420 and p0496 P0420 Catalyst efficiency below threshold Bank 1. P0496 Evap emission high purge flow fault

2006 Buick Rendezvous P0420 Code. I've tried everything. Replaced the downstream O2 sensor, replaced the Catalytic Converter, the thermostat, cleaned the fuel system and the coolant system, and I ...

Buick problems.... 2008 buick lucerne p0420 code and trunk won't open unrelated problems Code issue The P0420 code in a Buick Lucerne will often be thrown one of your oxygen sensors are not ...