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P0420 Diagnostic Trouble Code Discussion for January 2009

Catalyst Efficiency Below Normal (Bank 1)


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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2006 Jeep Grand Cherokee Laredo 4.7L No Start, Cuts out, Stall, Misfire, MIL Lamp on VIN: 1J8HR48P7C
P0420: Catalyst Efficiency Below Normal (Bank 1). Very hard start when cold, then start stall and will not take fuel on acceleration until warm - pops out of intake. Five spark plugs had the ground electrodes melted off and all eight plugs were white from heat. Will start immediately when cold with propane an...
January 02, 2009
2000 Mazda Protege ES 1.8L Poor Idle Quality, Hesitation VIN: JM1BJ2234Y
P0420: Catalyst Efficiency Below Normal (Bank 1). Ok, didn't think I was going to start the year off with a post. Got this Mazda and it runs like crap at idle and only idle. It has a little hesitation from a stop. It feels like a misfire, but I can't figure out which cylinder. The IDS doesn't have a misfire c...
January 02, 2009
2006 Jeep Grand Cherokee Laredo 4.7L No Start, Cuts out, Stall, Misfire, MIL Lamp on VIN: 1J8HR48P7C
P0420: Catalyst Efficiency Below Normal (Bank 1). Very hard start when cold, then start stall and will not take fuel on acceleration until warm - pops out of intake. Five spark plugs had the ground electrodes melted off and all eight plugs were white from heat. Will start immediately when cold with propane an...
January 05, 2009
2003 Toyota Camry SE 2.4L MIL Lamp on VIN: 4T1BE32K63
P0420: Catalyst Efficiency Below Normal (Bank 1). ... guys. I have a 2003 Toyota Camry LE with a 2.4L. Car is setting a p0420 catalyst code. Monitor b1s1 a/f sensor and b1s2 oxygen sensor. Rear oxygen sensor is reading around .74v, too high according to Modis, indicating a cat problem. Front a/f sensor readin...
January 15, 2009
2001 Cadillac DeVille 4.6L MIL Lamp on VIN: 1G6KD54Y31
P0420: Catalyst System Low Efficiency - Bank 1 (California). hello techs, lets see if you can help me with a cadillac that arrived today. Customers complaint is, the car was hard starting, and when it did start it would not idle and he had to keep it running by pushing the accelerar pedal down by foot, when letting go i...
January 23, 2009
1998 Jeep Grand Cherokee Limited 4.0L No Start, Cuts out, Stall, Misfire, MIL Lamp on VIN: 1J4FX5854W
P0420: Catalyst Efficiency Below Normal (Bank 1). I have a contant problem with this jeep started out with dieing while turning. now stalls out crank sensor, fuel pump, fuel filter, battery, coil has been replaced but im leaning to computer. any help is great thanks.
January 25, 2009
2000 Pontiac Sunfire GT 2.4L Poor Idle Quality, Misfire, MIL Lamp on VIN: 3G2JD12T3Y
P0420: Catalyst System Low Efficiency. ... p0300 (random misfire) and p0420 (cat efficiency) were in memory. both happened at idle, p0420 in park and p0300 in 2nd gear. both no vehicle speed - freeze frame does supply temp reading. When the tranny is in park it sounds like it runs lean. When it is ...
January 28, 2009
2006 Jeep Grand Cherokee Laredo 4.7L No Start, Cuts out, Stall, Misfire, MIL Lamp on VIN: 1J8HR48P7C
P0420: Catalyst Efficiency Below Normal (Bank 1). Very hard start when cold, then start stall and will not take fuel on acceleration until warm - pops out of intake. Five spark plugs had the ground electrodes melted off and all eight plugs were white from heat. Will start immediately when cold with propane an...
January 02, 2009
2000 Mazda Protege ES 1.8L Poor Idle Quality, Hesitation VIN: JM1BJ2234Y
P0420: Catalyst Efficiency Below Normal (Bank 1). Ok, didn't think I was going to start the year off with a post. Got this Mazda and it runs like crap at idle and only idle. It has a little hesitation from a stop. It feels like a misfire, but I can't figure out which cylinder. The IDS doesn't have a misfire c...
January 02, 2009
2006 Jeep Grand Cherokee Laredo 4.7L No Start, Cuts out, Stall, Misfire, MIL Lamp on VIN: 1J8HR48P7C
P0420: Catalyst Efficiency Below Normal (Bank 1). Very hard start when cold, then start stall and will not take fuel on acceleration until warm - pops out of intake. Five spark plugs had the ground electrodes melted off and all eight plugs were white from heat. Will start immediately when cold with propane an...
January 05, 2009
2003 Toyota Camry SE 2.4L MIL Lamp on VIN: 4T1BE32K63
P0420: Catalyst Efficiency Below Normal (Bank 1). ... guys. I have a 2003 Toyota Camry LE with a 2.4L. Car is setting a p0420 catalyst code. Monitor b1s1 a/f sensor and b1s2 oxygen sensor. Rear oxygen sensor is reading around .74v, too high according to Modis, indicating a cat problem. Front a/f sensor readin...
January 15, 2009
2001 Cadillac DeVille 4.6L MIL Lamp on VIN: 1G6KD54Y31
P0420: Catalyst System Low Efficiency - Bank 1 (California). hello techs, lets see if you can help me with a cadillac that arrived today. Customers complaint is, the car was hard starting, and when it did start it would not idle and he had to keep it running by pushing the accelerar pedal down by foot, when letting go i...
January 23, 2009
1998 Jeep Grand Cherokee Limited 4.0L No Start, Cuts out, Stall, Misfire, MIL Lamp on VIN: 1J4FX5854W
P0420: Catalyst Efficiency Below Normal (Bank 1). I have a contant problem with this jeep started out with dieing while turning. now stalls out crank sensor, fuel pump, fuel filter, battery, coil has been replaced but im leaning to computer. any help is great thanks.
January 25, 2009
2000 Pontiac Sunfire GT 2.4L Poor Idle Quality, Misfire, MIL Lamp on VIN: 3G2JD12T3Y
P0420: Catalyst System Low Efficiency. ... p0300 (random misfire) and p0420 (cat efficiency) were in memory. both happened at idle, p0420 in park and p0300 in 2nd gear. both no vehicle speed - freeze frame does supply temp reading. When the tranny is in park it sounds like it runs lean. When it is ...
January 28, 2009