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P0420 Diagnostic Trouble Code Discussion for July 2012

Catalyst Efficiency Below Normal (Bank 1)

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Trouble Ticket Help Requests for DTC P0420
Help Request Posted
1996 Chevrolet Impala SS 5.7L No Start, Stall VIN: 1G1BL52P9T
P0420: Catalyst System Low Efficiency (Bank 1). Fuel pressure at service port on rail is 20 psi.Fuel pressure on feed line(which is the bigger line) is 20 psi.When I disconnect line to test pressure fuel shoots out like a fire hose.Someone told me of a forum online that the pump wiring in fuel pump kit is b...
July 18, 2012