Questions & Answers for: Chevrolet Silverado 1500 p0420 code

P0420 & P0430 codes 99 silverado i have a 99 silverado1500 4.8L and im getting codes P0420 and P0430? i was told it was my o2 that needed to be replaced, but theres 4 of um 2 (pre&post)on each

...code P0420 - Catalyst System Efficiency Below Threshold it's very possible that your catalytic converter is still covered by the original emission warranty and might be replaced free of charge (would ...

...code will go away on its own after a couple normal condition drive cycles P0420=Catalyst System Efficiency Below Threshold Bank 1, This is no big deal,unless you want it to be,what the computer is ...

...code of P0420. Can you help? P0420 is a catalytic convertor efficiency below threshold, basically the convertor is not working to specs. As long as you are under 80,000 miles the convertor is covered ...

...is catilytic convertor no good and 446 is an evap problem P0300="random/multiple misfire detected" P0420=catalyst efficiency below threshold (bank 1) P0430=catalyst efficiency below threshold (bank

...if the engine is getting fuel and ignition first then go from there. P0420 mean Catalyst System Efficiency Below Threshold.If you want to know more ,please view Diagnostic Trouble Code Table

obd2 po420 code P0420.....Catalyst System Efficiency Below Threshold (Bank 1)

code p1415 and code p0420 Checkout this link and your codes can be found on pages 7 and 19 of 30 pages http://engine-codes.com/make/chevrolet/1

...P0420 what should i test? What size engine does your Sierra have? Usually, this code points to a bad catalytic converter but not always... since the rear (downstream) oxygen sensor could be bad (this ...