How can I remove the canister cap? - 2003 Saturn ION

Damaged/clogged evap canister. You probably overfilled fuel tank one too many times and caused damage. Evap canister is kind of charcoal filled canister located on your fuel system vent. When tank is overfilled gasoline reaches evap canister and and makes charcoal to became hard like clay. Once that happens fuel tank looses its vent and fuel pump cannot pull fuel because vaccum created inside fuel tank.

code p 0442 refers to evaporative emission(EVAP) system---small leak detected====causes--hose connections--intake leak--EVAP canister--EVAP canister purge valve
it also refers to --large leak detected====causes fuel cap loose, off---mechanical fault--hose connections---EVAP pressure sensor
code p 0441 refers to EVAP system--incorrect flow detected====causes hoses, intake leak-- EVAP canister purge valve
code p 0446 refers to EVAP system, vent control---circuit malfunction===causes--wiring---EVAP canister purge valve----ECM
if you can remember when the problem started ( after refueling) it may be that the cap is not fitted correctly
it could that in the fixing process , the wiring has not been correctly installed or the problem is the canister purge valve needs attention

If you mean the charcoal canister that removes excess vapours from the fuel system, open the fuel filler cap to relieve any pressure then simply remove the vacuum lines from the old canister, undo the mount and replace

look on front top right corner cylinder block. the 1.4 engine has the canister type oil filter.you need large socket and wrench to remove canister cap be sure replace the o ring in the oil filter cap housing.

P0446, This is a EVAP code,check the gas cap is the seal torn?Do you tighten the gas cap properly,If there is a circuit problem this will reside in the CCV (canister closed valve),VSV (pressure switching valve),or a disconnected hose at the charcoal canister,if anything just replace the gas cap first,clear the code and go from there

code PO455
EVAP Control System Large Leak Detected
Possible Causes:


Aftermarket EVAP hardware non-conforming to specifications Canister vent (CV) solenoid stuck open EVAP canister purge valve stuck closed, or canister damaged EVAP canister tube, EVAP canister purge outlet tube or EVAP return tube disconnected or cracked, or canister is damaged Fuel filler cap missing, loose (not tightened) or the wrong part Loose fuel vapor hose/tube connections to EVAP components Purge sensor or FTP sensor is out of calibration or has failed I would say that your gas cap is a good place to start.

The charcoal canister is most likely full of water as well. Detatch the lines to the cansiter, remove the canister, and shake... it should have no real heavyness to it and there should be no water, as it is filled with carbon pellets inside..

this is your evap cannister and/or purge valve. See picks and system operation below.

OPERATION Changes in atmospheric temperature cause fuel tanks to breathe, that is, the air within the tank expands and contracts with outside temperature changes. If an unsealed system was used, when the temperature rises, air would escape through the tank vent tube or the vent in the tank cap. The air which escapes contains gasoline vapors.
The Evaporative Emission Control System provides a sealed fuel system with the capability to store and condense fuel vapors. When the fuel evaporates in the fuel tank, the vapor passes through the EVAP emission valve, through vent hoses or tubes to a carbon filled evaporative canister. When the engine is operating the vapors are drawn into the intake manifold and burned during combustion..
A sealed, maintenance free evaporative canister is used. The canister is filled with granules of an activated carbon mixture. Fuel vapors entering the canister are absorbed by the charcoal granules. A vent cap is located on the top of the canister to provide fresh air to the canister when it is being purged. The vent cap opens to provide fresh air into the canister, which circulates through the charcoal, releasing trapped vapors and carrying them to the engine to be burned.
Fuel tank pressure vents fuel vapors into the canister. They are held in the canister until they can be drawn into the intake manifold. The canister purge valve allows the canister to be purged at a pre-determined time and engine operating conditions.
Vacuum to the canister is controlled by the canister purge valve. The valve is operated by the PCM. The PCM regulates the valve by switching the ground circuit on and off based on engine operating conditions. When energized, the valve prevents vacuum from reaching the canister. When not energized the valve allows vacuum to purge the vapors from the canister.
During warm up and for a specified time after hot starts, the PCM energizes (grounds) the valve preventing vacuum from reaching the canister. When the engine temperature reaches the operating level of about 120°F (49°C), the PCM removes the ground from the valve allowing vacuum to flow through the canister and purges vapors through the throttle body. During certain idle conditions, the purge valve may be grounded to control fuel mixture calibrations.
The fuel tank is sealed with a pressure-vacuum relief filler cap. The relief valve in the cap is a safety feature, preventing excessive pressure or vacuum in the fuel tank. If the cap is malfunctioning, and needs to be replaced, ensure that the replacement is the identical cap to ensure correct system operation.
OBD-II EVAP System Monitor
Some of the models covered in this guide have added system components due to the EVAP system monitor incorporated in the OBD-II engine control system. A pressure sensor is mounted on the fuel tank which measures pressure inside the tank, and a purge flow sensor measures the flow of the gases from the canister into the engine. The purge valve is now called the Vapor Management Valve (VMV). It performs the same functions as the purge valve, however it looks slightly different. A canister vent solenoid is mounted on the canister, taking the place of the vent cap, providing a source of fresh air to the canister.
The PCM can store trouble codes for EVAP system performance, a list of the codes is provided later in this information. Normal testing procedure can be used, see EVAP System Component Testing in this Section.

P0455 - EVAP Control System Leak Detected (No Purge Flow or Large Leak) The PCM monitors the complete EVAP control system for no purge flow, the presence of a large fuel vapor leak or multiple small fuel vapor leaks. The system failure occurs when no purge flow (attributed to fuel vapor blockages or restrictions), a large fuel vapor leak or multiple fuel vapor leaks are detected by the EVAP running loss monitor test with the engine running (but not at idle).

• After-market EVAP hardware (such as fuel filler cap) non-conforming to required specifications
• Disconnected or cracked fuel EVAP canister tube, EVAP canister purge outlet tube or EVAP return tube
• EVAP canister purge valve stuck closed
• Damaged EVAP canister
• Damaged or missing fuel filler cap
• Insufficient fuel filler cap installation
• Loose fuel vapor hose/tube connections to EVAP system components
• Blockages or restrictions in fuel vapor hoses/tubes (items also listed under disconnections or cracks)
• Fuel vapor control valve tube assembly or fuel vapor vent valve assembly blocked
• Canister vent (CV) solenoid stuck open
• Mechanically inoperative fuel tank pressure (FTP) sensor

Check for audible vacuum noise or significant fuel odor in the engine compartment or near the EVAP canister and fuel tank. ----------------------------------------------------------------------------- HX43 DTC P0457: CHECK FOR MISSING OR LEAKING FUEL FILLER CAP

• Check for missing fuel filler cap.
• Check for loose fuel filler cap.
• Check for possible cross-thread fuel filler cap condition.

Is a fault present concerning the proper installation of the fuel filler cap? Yes No REPLACE cross-threaded or damaged fuel filler cap. RECONNECT and TIGHTEN the fuel filler cap only one eighth turn so that the cap initially clicks by sound or touch. CLEAR Continuous Memory DTCs. COMPLETE an Evaporative Emission Running Loss Monitor Repair Verification Drive Cycle (refer to Section 2 , Drive Cycles). RERUN Quick Test . If DTC P0455 or P0457 is present, Go to HX44 . CLEAR Continuous Memory DTCs. COMPLETE an Evaporative Emission Running Loss Monitor Repair Verification Drive Cycle (refer to Section 2 , Drive Cycles). RERUN Quick Test .

For DTC P0455 still present: Go to HX44 .

Otherwise, INFORM the vehicle owner that it is important and necessary to immediately install the fuel filler cap after every refueling event. HX44 DTC P0455: VISUAL INSPECTION FOR SUBSTANTIAL EVAPORATIVE EMISSION SYSTEM LEAKS

• Check for missing fuel filler cap. If the cap is loose DO NOT DISTURB EVAP system.
• Verify that both the input port vacuum hose and EVAP return tube are attached to the EVAP canister purge valve. Note: If the EVAP canister-CV solenoid assembly is not accessible during this pinpoint test step, GO to Evaporative Emissions, Section 303-13 in the Workshop Manual for removal and installation instructions.
  
• Verify that the CV solenoid is properly seated on the EVAP canister (if possible).
• Visually inspect for disconnected or cracked fuel vapor hoses/tubes between the intake manifold, the EVAP canister purge valve, the EVAP canister, the fuel vapor vent valve assembly and if applicable the fuel vapor control valve tube assembly.
• Check for damage to the fuel filler pipe and the fuel tank.

Is a fault indicated? Yes No CONNECT or REPLACE fuel vapor hoses/tubes as required. REPLACE damaged EVAP system components (fuel filler pipe, fuel vapor vent valve assembly, fuel vapor control valve tube assembly, EVAP canister purge valve, FTP sensor and EVAP canister-CV solenoid assembly) as necessary. REFER to Evaporative Emissions, Section 303-13 in the Workshop Manual for removal and installation instructions. GO to HX45 . GO to HX45 . HX45 DTC P1443 and P0455: CHECK FOR EVAPORATIVE EMISSION SYSTEM LEAKS

Note: When checking for leaks or blockages in the EVAP system, energize (close) the canister vent (CV) solenoid through the scan tool for a maximum of nine minutes per pinpoint test step. Then de-energize the CV solenoid prior to performing the subsequent pinpoint test step. This is done to assure proper closing of the solenoid.

• Disconnect and plug the EVAP return tube (EVAP canister purge valve to intake manifold) at the intake manifold vacuum source.
• Connect scan tool.
• Key on, engine off.
• Access VPWR PID. If the voltage is not 12 volts or greater, GO to HX61 .
• Locate evaporative test port [marked EVAPORATIVE SERVICE PORT DO NOT USE UNREGULATED PRESSURE ABOVE 6.89 kPa (1 PSI)] near EVAP canister purge valve or EVAP canister.
• If vehicle is not equipped with the evaporative test port, GO to HX50 .
• Install the Rotunda Evaporative Emission System Leak Tester 310-F007 (134-00056) or equivalent at the evaporative test port.
• Close CV solenoid by accessing Output Test Mode on the scan tool.
• Select ALL OFF mode and push START button.
• Regulate the nitrogen or argon gas pressure on the tester to 3.48 kPa (14 in-H 2 O).
• Follow the instructions that come with the EVAP System Leak Tester and pressurize the EVAP system.
• Perform the EVAP system leak test.

Does the pressure on the EVAP system stay above 1.99 kPa (8 in-H 2 O) and pass the leak test? Yes No GO to HX46 . REMOVE the EVAP System Leak Tester from the evaporative test port and REINSTALL the test port cap. GO to HX50 .

make sure that the gas cap have a rubber gasket in it if it has accidentaly dropped off while you removed to fill the tnk it will not seal properly and create a vacum leak causing the ecm to turn on the light.

or did you have an accident or did you run over any thing that could have damaged the vapor canister at the bottom of the vehicle and if this is the case you will see the light on because a damaged canister can cause a vacum leak