DTC P0442:00, P0455:00, P0456:00 [MZI-3.7]: Notes

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DETECTION CONDITION & POSSIBLE CAUSE

DTC P0442:00 DTC P0455:00 DTC P0456:00	P0442:00: Evaporative emission system leak detected (small leak) P0455:00: Evaporative emission system leak detected (gross leak/no flow) P0456:00: Evaporative emission system leak detected (very small leak)
DETECTION CONDITION	P0442:00 indicates that a leak has been detected as small as 1 mm {0.040 in} in the EVAP system when there is less than 0 625 kPa (PID FTP_H2O displays "2.5") bleed-up over 15 s at 75% fuel fill. Bleed-up and evaluation time vary as a function of fuel fill level. The vapor generation limit is more than 0.625 kPa (PID FTP_H2O displays "2.5") over 120 s P0455:00: PCM measures the fuel tank pressure while applying engine vacuum to the EVAP system. If fuel tank pressure does not reach -1 74 kPa (PID FTP_H2O displays "-7.0") or above vacuum for a 30 s evaluation time, the PCM determines that the EVAP system is blocked or has a large leak. P0456:00 indicates that a fuel vapor leak from an opening as small as 0 508 mm {0.020 in} has been detected by the EVAP running loss monitor test.
POSSIBLE CAUSE	DTC P0442:00, P0456:00 After-market EVAP hardware (such as fuel-filler cap) not conforming to required specifications. Small holes or cuts in fuel vapor hoses/tubes (P0442:00, P0456:00) CV solenoid stays partially open on closed command Damaged, cross-threaded or loosely installed fuel-filler cap. EVAP system component seals leaking Purge solenoid leaking to atmosphere DTC P0455:00 After-market EVAP hardware (such as fuel-filler cap) not conforming to required specifications Disconnected or cracked CV solenoid valve tube, purge solenoid valve outlet tube, or EVAP return tube Loose, malfunctioning, damaged or missing fuel-filler cap Loose fuel vapor hose/tube connections to EVAP system components Blockages or restrictions in fuel vapor hoses/tubes between engine and fuel tank pressure sensor. Rollover valve or fuel shut-off valve blocked CV solenoid valve stuck open EVAP purge solenoid valve stuck closed or blockage Mechanically inoperative Fuel tank pressure sensor. Damaged charcoal canister

DTC P0442:00
DTC P0455:00
DTC P0456:00

P0442:00: Evaporative emission system leak detected (small leak)
P0455:00: Evaporative emission system leak detected (gross leak/no flow)
P0456:00: Evaporative emission system leak detected (very small leak)

DETECTION CONDITION

P0442:00 indicates that a leak has been detected as small as 1 mm {0.040 in} in the EVAP system when there is less than 0 625 kPa (PID FTP_H2O displays "2.5") bleed-up over 15 s at 75% fuel fill. Bleed-up and evaluation time vary as a function of fuel fill level. The vapor generation limit is more than 0.625 kPa (PID FTP_H2O displays "2.5") over 120 s
P0455:00: PCM measures the fuel tank pressure while applying engine vacuum to the EVAP system. If fuel tank pressure does not reach -1 74 kPa (PID FTP_H2O displays "-7.0") or above vacuum for a 30 s evaluation time, the PCM determines that the EVAP system is blocked or has a large leak.
P0456:00 indicates that a fuel vapor leak from an opening as small as 0 508 mm {0.020 in} has been detected by the EVAP running loss monitor test.

POSSIBLE CAUSE

DTC P0442:00, P0456:00

After-market EVAP hardware (such as fuel-filler cap) not conforming to required specifications.
Small holes or cuts in fuel vapor hoses/tubes (P0442:00, P0456:00)
CV solenoid stays partially open on closed command
Damaged, cross-threaded or loosely installed fuel-filler cap.
EVAP system component seals leaking
Purge solenoid leaking to atmosphere

DTC P0455:00

After-market EVAP hardware (such as fuel-filler cap) not conforming to required specifications
Disconnected or cracked CV solenoid valve tube, purge solenoid valve outlet tube, or EVAP return tube
Loose, malfunctioning, damaged or missing fuel-filler cap
Loose fuel vapor hose/tube connections to EVAP system components
Blockages or restrictions in fuel vapor hoses/tubes between engine and fuel tank pressure sensor.
Rollover valve or fuel shut-off valve blocked
CV solenoid valve stuck open
EVAP purge solenoid valve stuck closed or blockage
Mechanically inoperative Fuel tank pressure sensor.
Damaged charcoal canister