Code Issues P0420!
06-12-2012, 04:26 PM
#1
Code Issues P0420!
I recently failed inspection, again. The first time was for cylinder misfires. I cleaned the gasket and the cylinders and the problem seemed to be gone. The check engine light went off for about a week and is back. The code i failed for P0420. I am not sure how to fix this issue!
06-13-2012, 06:52 PM
#3
^^^
Huh?
P0420 means that the post catalyst (aka:downstream) oxygen sensor has detected that the catalytic converter is operating below efficiency. In other words, it's not working correctly. Generally speaking this code means your catalytic converter is bad and judging by the fact the code before this one was a misfire code, I'd bet some money that's the actual problem here. If your misfire was due to an ignition problem, that cylinder was experiencing incomplete combustion and allowing unburned fuel to exit into the exhaust and then into the catalytic converter. Because the converter already superheats itself naturally, these unburned fuel will cause it to become even hotter. Operating at high temperatures for too long (sometimes even short durations) can cause the converter to burn itself out because it's starts combusting the fuels which in turn rids the converter of all it's precious metals deeming it useless. I've seen misfires actually cause these things to glow red with heat! You could (and should) try running a SeaFoam treatment through the intake to remove any possible excessive carbon accumulation that could be hindering its performance BUT like I said, you'll more than like end up having to just replace it anyway.
BTW, when it comes to replacing it, DO NOT buy a cheap, aftermarket catalytic converter from anybody. You will waste your money and time...trust me. I have so many people referred to my shop after replacing their catalytic converters and then being told there's another issue because code P0420 still exists. 99.9% of the time it ends up being a low quality catalytic converter.
Huh?
P0420 means that the post catalyst (aka:downstream) oxygen sensor has detected that the catalytic converter is operating below efficiency. In other words, it's not working correctly. Generally speaking this code means your catalytic converter is bad and judging by the fact the code before this one was a misfire code, I'd bet some money that's the actual problem here. If your misfire was due to an ignition problem, that cylinder was experiencing incomplete combustion and allowing unburned fuel to exit into the exhaust and then into the catalytic converter. Because the converter already superheats itself naturally, these unburned fuel will cause it to become even hotter. Operating at high temperatures for too long (sometimes even short durations) can cause the converter to burn itself out because it's starts combusting the fuels which in turn rids the converter of all it's precious metals deeming it useless. I've seen misfires actually cause these things to glow red with heat! You could (and should) try running a SeaFoam treatment through the intake to remove any possible excessive carbon accumulation that could be hindering its performance BUT like I said, you'll more than like end up having to just replace it anyway.
BTW, when it comes to replacing it, DO NOT buy a cheap, aftermarket catalytic converter from anybody. You will waste your money and time...trust me. I have so many people referred to my shop after replacing their catalytic converters and then being told there's another issue because code P0420 still exists. 99.9% of the time it ends up being a low quality catalytic converter.
Last edited by yungone501; 06-13-2012 at 06:54 PM.
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StreetKA (06-13-2012)
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