IM GETTING THE PO420 CODE ON MY 2003 4.3L V6 CHEVY S-10, I RECENTLY CHANGED OUT THE CATALYTIC CONVERTER, A COUPLE WEEKS LATER MY SERVICE ENGINE SOON LIGHT CAME ON. SINCE THEN I HAVE PUT IN NEW AIR FILTER, SPARK PLUGS, SPARK PLUG WIRES, I ADDED A BOTTLE OF GUMMOUT FUEL SYSTEM CLEANER TO THE GAS TANK, ALSO HAVE DONE AN OIL CHANGE,THE LIGHT IS STILL ON!! ANY HELP/SUGGESTIONS WILL HELP THANKS FOR HELP OSCAR
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Re: PO420 CODE ON CHEVY S10
The code means---
Catalyst Efficiency Below Threshold (Bank 1)
Please make sure there is no air entering the engine behind the maf, such as a vacuum leak or leaks in ducting between the maf and the throttle body.
If that's no the case then its an issue with injectors clogging and they are not working due to "fretting". This "fretting" is electrical terminals to injectors getting oxidation on them and is fixed by unplugging them and replugging them in. The fix is to put a small dab of die-electric grease on the terminals.
I would suggest an injector service with the new GM procedure using "Top Engine Cleaner". This may be all you need but that P0420 bothers me. P0420, Catalyst System Efficiency Below Threshold, can be set by a poor connection at the PCM or a damaged wiring harness.
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I have a 2000 chevy s 10 4.3 4wd that ran good then it started hesitating like it has no power , after warming up and trying to go more than 25 pmh, checked plugs , wires, distrib all seems good any ideas???
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One of the most annoying is the persistent PO420 diagnostic code (Catalyst System ... not only shows its teeth when the catalytic converter is on the blink, but can also be ... Most, if not all, catalytic converter failures are caused by a problem or ...
Repair information for the OBD-II trouble code P0420 - Catalyst System Efficiency ... If they have failed, it is likely due to something else that caused it to fail. ... the catalytic converter is broken or failed, it may be restricting the exhaust which will ...
for the code po420, you need to patch the leak first then clear the code and dirve the car one or two days to see the code come back on, if not you just fix the problem. but I bet it is your catalytic converter is bad, the rattle sound is not coming from the engine, it is from the catalytic converter, use a seth pole to listen, the catalytic converter is right infront and it is part of the exhaust mainfold.
Hi, the usual cause is a worn out catalytic converter, but this code may also set due to a rich mixture. Check your tailpipe for soot or black film. If the pipe looks OK, replace the catalytic converter. If your converter is recently replaced or you have soot, please get back to me for a different plan of action.
For the lean condition I wound look for vacuum leaks.I you don`t find any then replace the o2 sensor for bank 1.As for the po420 if the exhaust system is not bent or damaged you will have to replace the catalytic converter.The catalytic converter has a longer warranty then the regular vehicle warranty itself so call the dealership and find out if the converter is still under warranty.The usual warranty I believe is around 80k.mileage years is 7 or 8 not positive.Hope this helps.Good luck.
PO420 code is for catalyst system efficiency below threshold (bank 1) Usually it means that it is time for a new catalytic converter on bank number 1. Cylinder bank number 1 is always the bank with the number 1 spark plug in it.
The p0300 code is a random missfire code sometimes caused by bad spark plugs and wires, if you have not done a tune up, it's time for one. now, the p0420 code is for catalyst efficiency below threshold, basically, your catalytic converter is bad and may need to be replaced. Sometimes repairing the random missfire can eventually clear the p0420 code. your car is not burning fuel properly, therefore the catalytic converter is getting dirty. Also, if you notice blue smoke coming out the tail pipe, then that's the cause for a failing catalytic converter as oil is getting to the combustion chamber and being burned off through the exhaust.
The oxygen sensors in front and behind the converter are reporting too similar
Check for exhaust leaks at the manifold, pipes, catalytic converter.
Replace Coolant Temperature Sensor
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).
the problem is with the catalytic converter, there is a specific emission threshold that the exhaust must maintained. when it falls below this, you get this code. i just had to replace my converter for the same problem