Have a 2002 Eclipse RS which I just bought from a dealer...The "service engine soon" light came on...OBDII code P0421, and a P0421 pending. Cleared the codes and it went about 6 days before reappearing...appeared on cold days both times. 112,000 miles, any reason to worry imnediately?
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.
When the service engine soon light (Also called the check engine light or engine management light) is turned on this is to alert you to the fact that Powertrain Control Module (computer) has detected a failure somewhere in the systems it controls you may not feel any difference in the way the engine runs, this can be the transmission or the engine or emission system, there are fault codes set in the modules memory for these faults. What needs to happen now is to have the powertrain control module scanned with a special tool called an OBD2 electronic engine control scanner or a OBD2 code reader. Once the code(s) are read then you must perform the diagnostics for each code and make the appropriate repairs based on the findings of the diagnosis that was performed, this is called doing "Pinpoint" testing.
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