2002 Mitsubishi Galant "p0421" Questions

Is it possible to get a P0421 code from the OBD computer when the engine light is not on? Yes it is and it would mean that the problem that caused the P0421 has either been corrected or is ...

please interpret code p0421 P0421 : Warm Up Catalyst Efficiency Below Threshold

1999 mitsubishi galant es engine light code P0421 http://www.obd-codes.com/p0421

2 trouble code p0421 and p0421 pd OBDII scanned describing something like warm up catalyst threshold bank....Please help I believe this has to do with your catalytic converter. Sounds like it might be

...4cylinder Mitsubishi Galant. The Service engine light originally came on in June 2006. The code was P0421. I was told it was the oxygen sensor and not a problem, by a couple of mechanics. Well, late ...

Spinning My Wheels!! ---- P0421 Code Mitsubishi Galant My car is a 2003 Mitsubishi Galant 4cylinder. The service engine light came on with the P0421 code in June 2006, I was told it was the front O2 ...

I have code of p0421 Basically this means that the oxygen sensor downstream of the catalytic converter on bank 1 is detecting that the converter is not working as efficiently as it should be ...

MITSUBISHI LANCER 2003 CODE; P0421 The code means Warm-up catalyst efficiency below threshold.....

po421 code obd P0421....Warm Up Catalyst Efficiency Below Threshold (Bank 1) the the heaters on the O2 sensors -two white wires on sensor check for continueity

What does the code P0421 mean http://engine-codes.com/p0421_mitsubishi.html