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P0420 Diagnostic Trouble Code Discussion for May 2009

Catalyst Efficiency Below Normal (Bank 1)


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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
2001 Subaru Forester 2.5L spark knock VIN: JF1SF65561
P0420: Catalyst Efficiency Below Normal (Bank 1). Spark knock when engine loaded at highway speed (customer says since new - his first visit with us). Starts and runs fine. Scan data normal (map,temp,airflow). Plugs are recent - one was loose. Ign. timing correct at idle. A new knock sensor seemed to correct ...
May 07, 2009
2001 Audi TT 1.8L MIL Lamp on VIN: TRUWX28N61
P0420: catalyst efficiency. I'm looking for some answer here, the p1612 is my concern the pcm reports the correct coding even tho its setting a code for being incorrect. My thoughts are a bad pcm? The equipment, trans, engine, etc. indicates coding 07700 and this agrees with factory audi...
May 08, 2009
1997 Jeep Grand Cherokee Limited 5.2L Excessive Emissions VIN: 1J4GZ78Y9V
P0420: Catalyst Efficiency Below Normal (Bank 1). No other codes fuel tirm ok no sign of running lean or coolant leaks or running rich. O2 start switching at same speed at cruise. Useing after market direct fix cat.
May 11, 2009
2004 Chrysler Town & Country (Van) Limited 3.8L MIL Lamp on VIN: 2C8GP64L64
P0420: Catalyst system efficiency below threshold. ... country that keeps storing a P0420 code. Scan computer system and found upstream o2 voltage staying between 325mv and 225mv. Replaced upstream o2 sensor. Customer took vehicle came back week later with same code. Recheck still same readings on O2. Replace ...
May 14, 2009
1999 Toyota Camry LE 2.2L Surge, Cuts out, Stall, starts in 2nd gear VIN: JT2BG22K5X
P0420: Catalyst Efficiency Below Normal (Bank 1). ... Genisys found P0420 and replaced cat with rear O2 sensor. No more MIL. replaced VSS because speedometer was very eractic. still was eratic intermittently. tried an ECM/PCM with no change. After the vehicle has been vehicle over 15 miles then it begins to s...
May 17, 2009
2000 Toyota Tacoma Pre Runner 3.4L No Start, Poor Idle Quality, MIL Lamp on VIN: 5TESN92N8Y
P0420: Catalyst Efficiency Below Normal (Bank 1). Hello everybody,Vehicle was towed in, customer said he was driving on the freeway and vehicle stalled and would not restart. Vehicle cranks, and will start and run very sluggish for about 2-3 seconds and then dies. Checked the basics: fuel, spark, noid fire an...
May 18, 2009
1999 Honda CR-V EX 2.0L MIL Lamp on VIN: JHLRD1863X
P0420: Catalyst Efficiency Below Threshold (Bank 1). ... out with a intermittent stalling problem,which we later fixed with an Igniter. But not before this vehicle set a P0420 code. I checked the o2 sensors at cruise and the post-cat o2 mirrored the pre-cat o2. Looked like a classic defective Honda catalyst to m...
May 19, 2009
1997 Jeep Grand Cherokee Limited 5.2L Excessive Emissions VIN: 1J4GZ78Y9V
P0420: Catalyst Efficiency Below Normal (Bank 1). No other codes fuel tirm ok no sign of running lean or coolant leaks or running rich. O2 start switching at same speed at cruise. Useing after market direct fix cat.
May 20, 2009
2001 Subaru Impreza Outback 2.2L MIL Lamp on VIN: JF1GF48511
P0420: Catalyst Efficiency Below Normal (Bank 1). ... with code p0420.Repalced convertor and air/fuel sensor,along with rear 02.2months later car returned with same code replaced convertor under warrenty.Now car back with same code agian.Mileage at the first repair was 172237.Mileage now is 177375.Convertor i...
May 21, 2009
2000 Toyota Tacoma Pre Runner 3.4L No Start, Poor Idle Quality, MIL Lamp on VIN: 5TESN92N8Y
P0420: Catalyst Efficiency Below Normal (Bank 1). Hello everybody,Vehicle was towed in, customer said he was driving on the freeway and vehicle stalled and would not restart. Vehicle cranks, and will start and run very sluggish for about 2-3 seconds and then dies. Checked the basics: fuel, spark, noid fire an...
May 26, 2009
2001 Subaru Forester 2.5L spark knock VIN: JF1SF65561
P0420: Catalyst Efficiency Below Normal (Bank 1). Spark knock when engine loaded at highway speed (customer says since new - his first visit with us). Starts and runs fine. Scan data normal (map,temp,airflow). Plugs are recent - one was loose. Ign. timing correct at idle. A new knock sensor seemed to correct ...
May 07, 2009
2001 Audi TT 1.8L MIL Lamp on VIN: TRUWX28N61
P0420: catalyst efficiency. I'm looking for some answer here, the p1612 is my concern the pcm reports the correct coding even tho its setting a code for being incorrect. My thoughts are a bad pcm? The equipment, trans, engine, etc. indicates coding 07700 and this agrees with factory audi...
May 08, 2009
1997 Jeep Grand Cherokee Limited 5.2L Excessive Emissions VIN: 1J4GZ78Y9V
P0420: Catalyst Efficiency Below Normal (Bank 1). No other codes fuel tirm ok no sign of running lean or coolant leaks or running rich. O2 start switching at same speed at cruise. Useing after market direct fix cat.
May 11, 2009
2004 Chrysler Town & Country (Van) Limited 3.8L MIL Lamp on VIN: 2C8GP64L64
P0420: Catalyst system efficiency below threshold. ... country that keeps storing a P0420 code. Scan computer system and found upstream o2 voltage staying between 325mv and 225mv. Replaced upstream o2 sensor. Customer took vehicle came back week later with same code. Recheck still same readings on O2. Replace ...
May 14, 2009
1999 Toyota Camry LE 2.2L Surge, Cuts out, Stall, starts in 2nd gear VIN: JT2BG22K5X
P0420: Catalyst Efficiency Below Normal (Bank 1). ... Genisys found P0420 and replaced cat with rear O2 sensor. No more MIL. replaced VSS because speedometer was very eractic. still was eratic intermittently. tried an ECM/PCM with no change. After the vehicle has been vehicle over 15 miles then it begins to s...
May 17, 2009
2000 Toyota Tacoma Pre Runner 3.4L No Start, Poor Idle Quality, MIL Lamp on VIN: 5TESN92N8Y
P0420: Catalyst Efficiency Below Normal (Bank 1). Hello everybody,Vehicle was towed in, customer said he was driving on the freeway and vehicle stalled and would not restart. Vehicle cranks, and will start and run very sluggish for about 2-3 seconds and then dies. Checked the basics: fuel, spark, noid fire an...
May 18, 2009
1999 Honda CR-V EX 2.0L MIL Lamp on VIN: JHLRD1863X
P0420: Catalyst Efficiency Below Threshold (Bank 1). ... out with a intermittent stalling problem,which we later fixed with an Igniter. But not before this vehicle set a P0420 code. I checked the o2 sensors at cruise and the post-cat o2 mirrored the pre-cat o2. Looked like a classic defective Honda catalyst to m...
May 19, 2009
1997 Jeep Grand Cherokee Limited 5.2L Excessive Emissions VIN: 1J4GZ78Y9V
P0420: Catalyst Efficiency Below Normal (Bank 1). No other codes fuel tirm ok no sign of running lean or coolant leaks or running rich. O2 start switching at same speed at cruise. Useing after market direct fix cat.
May 20, 2009
2001 Subaru Impreza Outback 2.2L MIL Lamp on VIN: JF1GF48511
P0420: Catalyst Efficiency Below Normal (Bank 1). ... with code p0420.Repalced convertor and air/fuel sensor,along with rear 02.2months later car returned with same code replaced convertor under warrenty.Now car back with same code agian.Mileage at the first repair was 172237.Mileage now is 177375.Convertor i...
May 21, 2009
2000 Toyota Tacoma Pre Runner 3.4L No Start, Poor Idle Quality, MIL Lamp on VIN: 5TESN92N8Y
P0420: Catalyst Efficiency Below Normal (Bank 1). Hello everybody,Vehicle was towed in, customer said he was driving on the freeway and vehicle stalled and would not restart. Vehicle cranks, and will start and run very sluggish for about 2-3 seconds and then dies. Checked the basics: fuel, spark, noid fire an...
May 26, 2009