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P0421 Diagnostic Trouble Code Discussion for October 2010

Warmup Catalyst Efficiency Low (Bank 1)


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Trouble Ticket Help Requests for DTC P0421
Help Request Posted
2002 Mazda Protege ES 2.0L Misfire, MIL Lamp on VIN: JM1BJ22572
P0421: Warmup Catalyst Efficiency Below Normal (Bank 1). ... random, while driving the vehicles does not jerk backfire or do any normal misfire tactics, nor at idle with brake on and in gear accel pedal to floor no misfire from engine. the code reappears while driving, but no noticeable misfire occurs, or shudder/sh...
October 18, 2010
2002 Mazda Protege ES 2.0L Misfire, MIL Lamp on VIN: JM1BJ22572
P0421: Warmup Catalyst Efficiency Below Normal (Bank 1). ... random, while driving the vehicles does not jerk backfire or do any normal misfire tactics, nor at idle with brake on and in gear accel pedal to floor no misfire from engine. the code reappears while driving, but no noticeable misfire occurs, or shudder/sh...
October 20, 2010
2002 Mazda Protege ES 2.0L Misfire, MIL Lamp on VIN: JM1BJ22572
P0421: Warmup Catalyst Efficiency Below Normal (Bank 1). ... random, while driving the vehicles does not jerk backfire or do any normal misfire tactics, nor at idle with brake on and in gear accel pedal to floor no misfire from engine. the code reappears while driving, but no noticeable misfire occurs, or shudder/sh...
October 18, 2010
2002 Mazda Protege ES 2.0L Misfire, MIL Lamp on VIN: JM1BJ22572
P0421: Warmup Catalyst Efficiency Below Normal (Bank 1). ... random, while driving the vehicles does not jerk backfire or do any normal misfire tactics, nor at idle with brake on and in gear accel pedal to floor no misfire from engine. the code reappears while driving, but no noticeable misfire occurs, or shudder/sh...
October 20, 2010