P0420 Diagnostic Trouble Code Discussion for August 2010
Catalyst Efficiency Below Normal (Bank 1)
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| Help Request | Posted | |
| 2004 Cadillac Escalade 6.0L Poor Idle Quality, Misfire, MIL Lamp on VIN: 1GYEK63N74 P0420: Catalyst System Low Efficiency (Bank 1). ... light on check codes code p0300 and p0420. Check misfire data #2 cylinder had multiple misfires counts 829. some on other cylinders too but number 2 the worst. Check plugs and wires they had been changed. Check fuel pressure ok 55psi. Let vehicle set overn... |
August 26, 2010 | |
| 2000 Chevrolet Express 1500 4.3L MIL Lamp on VIN: 1GBFG15W6Y P0420: Catalyst System Low Efficiency (Bank 1). hello fellow technicians. truck came in for misfire. found 4 codes listed. also i dont understand why i have a a.i.r code, this truck has no a.i.r system. atleast no relay, fuse or pump. well anyways wires were arcing and plugs were .030 worn over gap. replace... |
August 30, 2010 | |
| 2005 Ford F-350 Super Duty XL 5.4L Hesitation, Misfire, MIL Lamp on VIN: 1FTWW31545 P0420: Bank 1 Cat Efficiency Low. This truck intermittently falls on its face while accelerating, its happening more and more. Both 02 sensors stay at around .95V and short term fuel trim is -20%. Map sensor voltage is at 4.99V. Its like this thing cannot get enough air. I did find a TSB #07M0... |
August 31, 2010 |
