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P0420 Diagnostic Trouble Code Discussion for March 2007

Catalyst Efficiency Below Normal (Bank 1)


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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
1998 Mazda MPV ES 3.0L Hesitation, Surge, MIL Lamp on VIN: JM3LV5235W
P0420: Catalyst Efficiency Below Normal (Bank 1). ... road. It will start but hesitates badly. We pulled codes and found P0300, P0420 and P1345. Checked the plugs and found them to be worn down to electrode so we replaced them.Runs better but far from normal. 02 bank 1 is switc...
March 02, 2007
1999 Subaru Forester L 2.5L MIL Lamp on VIN: JF1SSF6359
P0420: Catalyst Efficiency Below Normal (Bank 1). ... came in with a ck engine light on code p0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD BANK 1 was monitoring front and rear oxygen sensors and found that I am only getting 2 to 3 in 10 sec.at 2500 rpm and the rear oxygen sensor has about 1 to 2 . when I s...
March 05, 2007
1999 Subaru Forester L 2.5L MIL Lamp on VIN: JF1SSF6359
P0420: Catalyst Efficiency Below Normal (Bank 1). ... came in with a ck engine light on code p0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD BANK 1 was monitoring front and rear oxygen sensors and found that I am only getting 2 to 3 in 10 sec.at 2500 rpm and the rear oxygen sensor has about 1 to 2 . when I s...
March 06, 2007
2003 Toyota Tundra Limited 4.7L MIL Lamp on VIN: 5TBBT48163
P0420: Catalyst Efficiency Below Normal (Bank 1). Almost every time I see these codes on a vehicle it ends up needing new cats. A few times I've seen a TSB indicating an ECM update that changes the effeciency threshold. This truck has no such TSB's. There are no codes to indicate a fault with the O2 sensors t...
March 08, 2007
2002 Volkswagen Beetle GLS 2.0L MIL Lamp on VIN: 3VWCK21C82
P0420: catalyst system -too lean-intermit. ... [cat] and P0455 [evap leak] We looked at the oxy sensors with our Snap on scanner. At 2500 rpm the front was fluctuating between 1.460 nad 1.580 volts [milivolts??]. The rear was between .450 and .550.. Do we have a bad cat., oxy sensors or both here ?? We...
March 15, 2007
2001 Saab 9-5 SE 3.0L MIL Lamp on VIN: YS3EF58Z11
P0420: catilist ineffeciency. Any help would be appreciated. This car runs great,have done all repairs in related repairs history. Does anybody have a clue what else other than the catilitic convertor would cause this code to keep returning. These catilic convertors are after market and no...
March 29, 2007
1998 Mazda MPV ES 3.0L Hesitation, Surge, MIL Lamp on VIN: JM3LV5235W
P0420: Catalyst Efficiency Below Normal (Bank 1). ... road. It will start but hesitates badly. We pulled codes and found P0300, P0420 and P1345. Checked the plugs and found them to be worn down to electrode so we replaced them.Runs better but far from normal. 02 bank 1 is switc...
March 02, 2007
1999 Subaru Forester L 2.5L MIL Lamp on VIN: JF1SSF6359
P0420: Catalyst Efficiency Below Normal (Bank 1). ... came in with a ck engine light on code p0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD BANK 1 was monitoring front and rear oxygen sensors and found that I am only getting 2 to 3 in 10 sec.at 2500 rpm and the rear oxygen sensor has about 1 to 2 . when I s...
March 05, 2007
1999 Subaru Forester L 2.5L MIL Lamp on VIN: JF1SSF6359
P0420: Catalyst Efficiency Below Normal (Bank 1). ... came in with a ck engine light on code p0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD BANK 1 was monitoring front and rear oxygen sensors and found that I am only getting 2 to 3 in 10 sec.at 2500 rpm and the rear oxygen sensor has about 1 to 2 . when I s...
March 06, 2007
2003 Toyota Tundra Limited 4.7L MIL Lamp on VIN: 5TBBT48163
P0420: Catalyst Efficiency Below Normal (Bank 1). Almost every time I see these codes on a vehicle it ends up needing new cats. A few times I've seen a TSB indicating an ECM update that changes the effeciency threshold. This truck has no such TSB's. There are no codes to indicate a fault with the O2 sensors t...
March 08, 2007
2002 Volkswagen Beetle GLS 2.0L MIL Lamp on VIN: 3VWCK21C82
P0420: catalyst system -too lean-intermit. ... [cat] and P0455 [evap leak] We looked at the oxy sensors with our Snap on scanner. At 2500 rpm the front was fluctuating between 1.460 nad 1.580 volts [milivolts??]. The rear was between .450 and .550.. Do we have a bad cat., oxy sensors or both here ?? We...
March 15, 2007
2001 Saab 9-5 SE 3.0L MIL Lamp on VIN: YS3EF58Z11
P0420: catilist ineffeciency. Any help would be appreciated. This car runs great,have done all repairs in related repairs history. Does anybody have a clue what else other than the catilitic convertor would cause this code to keep returning. These catilic convertors are after market and no...
March 29, 2007