120K miles No major accident damage Everything is functional
Trouble Code: P0421
Main Catalyst Efficiency Deterioration (Bank 1)
Trouble Code Conditions: DTC P0136, P0139 and P0140 not set, engine running at 3000 rpm or high in closed loop at 45-60 mph for 140 seconds, and the PCM detected the rear HO2S and front HO2S signals were too similar.
Possible Causes:
Air leaks at the exhaust manifold or in the exhaust pipes.
Catalytic converter is damaged or has failed .
Front HO2S or rear HO2S is contaminated with fuel or moisture.
Front HO2S or rear HO2S heater is damaged or has failed.
Front HO2S or rear HO2S is contaminated with fuel or moisture.
Trouble Code: P0431
Main Catalyst Efficiency Deterioration (Bank 2)
Trouble Code Conditions: DTC P0150, P0154, P0159, P0158, P0160 and P0161 not set, engine started, engine running at 3000 rpm or high in closed loop at 45-60 mph for 140 seconds, and the PCM detected the rear HO2S and front HO2S signals were too similar in the Catalyst Monitor test.
Possible Causes:
Air leaks at the exhaust manifold or in the exhaust pipes.
Catalytic converter is damaged or has failed.
Front HO2S or rear HO2S is contaminated with fuel or moisture.
Front HO2S or rear HO2S heater is damaged or has failed.
Front HO2S or rear HO2S is contaminated with fuel or moisture .
SOURCE: P0421 code on recently purchased(from dealer) 2002 RS
Hi,
So you have a P0421.
A code P0421 may mean that one or more of the following has happened:
As far as running conditions if it performs normally, you most likely need a catalytic converter. The good part of this is there shouldn't be any abnormal running conditions, so it should be fine unless the engine is running very rich for some reason. (it will usually smell badly when this happens) However, on rare occasions the cat can get hot and melt down causing an exhaust restriction..bad gas mileage, low power, and possible fire potential, but most likely this is not the case. (this is generally speaking here and covering all the bases... )
The most common thing with P0421 that the fuel injection computer detects that the cat is not performing to federal specs an need to be replaced. You will need to have it fixed before your vehicle inspection.
Good luck and I hoped this helped you.
SOURCE: Hi i get codes P0431 and P0174 on a 2002 Kia
I have tried everything, but I am coming to the conclusion that I have a bad pcv letting in too much air. The concensus of how to fix it seems to be to clean the MAF with some electical cleaner or brake cleaner. Basically, you are getting too much air into the throttle body after the MAF or a dirty MAF.
SOURCE: What are codes P1492, P0421 & P0431 on the
po421 warm up catalyst efficiency below threshhold bank 1, 431 same on bank 2..
SOURCE: how many ignition coils hava a kia sedona??????
6 ignition coils, one for each cylinder. 3.5 SFI DOHC.
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