1997 Chevrolet C1500 "p0420" Questions

I keep getting code p0420. I replaced 2 cats, all 4 o2 sensors, plugs, wires, cap & rotor, cleaned air filter, sprayed maf sensor, new fuel injection spider, 2 mufflers. What is the problem? are ...

2002 chevy avalanche. service engine soon light went to auto zone and got code p0420. what do i do What size engine does this have Rose? It's an 02 sensor/converter issue. When both 02 sensors read ...

P0420 I just bought-V6,150,000 miles,converter was 1/2 gone + ratteling.Replaced w/Walker direct fit and all 3 new O2 sensors.No sign of coolant leak.No external vacuum leaks.Old spark plugs looked ...

have a 20088 fully loaded nissan quest with code p0420 plugs and coils have been replaced already drives fine https://www.fixdapp.com/blog/p0420 https://www.fixdapp.com/blog/p0420 https://mechanicbase

P0420 2003 Toyota Corolla, HELP! FYI more background on a P0420 - http://p0420.com p0420 is a code for catalytic converter efficiency, the cat will need to be replaced. in some instances a software ...

what is p0420 on a 2006 chevy cobalt 2.2l P0420 is a code for the catalytic converter. It has failed the efficiency test. See this post for the full story on P0420 trouble codes ...

TROUBLE CODE P0420 CHECK ENGINE CAME AND I HAD IT CHECKED AT AUTO ZONE THE CODE INDICATED WAS P0420. VEHICLE ISN'T MISFIRING OR RUNNING BAD. P0420 isnt a misfiring code; this code P0420 is refer ...

Error codes: P0420 AND P0446 1996 Oldsmobile Bravada 4.3 liter. Error code: P0420 and will not pass emissions. Also code: P0446, I realize that the P0420 may be a 02 sensor, but I am looking for ...

P0420. States O2 sensor. Bank 1. Faulty spark plugs. Or hvac leak. Or catalytic converter. Where do I start to fix this problem. Just purchased original O2 sensor. Will start there then spark plugs. ?

my 2005 chevy equinox keeps showing problem code P0420 How do I fix this problem? 0 2 sensor near the catalytic converter or replace the catalytic converter The downstream O2 sensor reading should be ...