I have 2006 chevy equinox code po455 I change the fuel cap and the purge evap valve but my code comes back what else could it be?

Possible causes
- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking
What does this mean? Tech notes
The P0455 it's a very common code, because the code is set if the gas cap is loose or missing. Start by tighten the gas cap and clearing the code. In most cases the code can be clear by disconnecting the car battery for about 30 minutes.
What does this mean? When is the code detected?
Evaporative Emission System (EVAP) control system has a very large leak such as fuel filler cap fell off, EVAP control system does not operate properly.
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible a noticeable fuel odor caused by the release of fuel vapors
P0455 Mitsubishi Description
This diagnosis detects leaks in the Evaporative Emission System (EVAP) purge line using engine intake manifold vacuum. If pressure does not increase, the Engine Control Module (ECM) will check for leaks in the line between the fuel tank and EVAP canister purge volume control solenoid valve under the following vacuum test condition.
The vacuum cut valve bypass valve is opened to clear the line between the fuel tank and the EVAP canister purge volume control solenoid valve. The EVAP canister vent control valve will then be closed to shut the EVAP purge line off. The EVAP canister purge volume control solenoid valve is opened to depressurize the EVAP purge line using intake manifold vacuum. After this depressurization is implemented, the EVAP canister purge volume control solenoid valve will be closed.

Read more: http://engine-codes.com/p0455_mitsubishi.html#ixzz3NlVyARyX

codes po441 po442 po455 po456. code po441 - EVAP system no flow during purge conditions.code po442 -EVAP system small leak detected conditions. code po455 - EVAP system large leak detected conditions.code po456 - EVAP system very small leak detected. possible causes loose damaged missing fuel cap.fuel tank sensor disconnected or failed. ORING on top fuel sending unit leaking.purge valve vapor line clogged disconnected or purge solenoid failed.vent solenoid not closing or has failed.

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.

CODE PO455 - EVAP SYSTEM LARGE LEAK DETECTED. POSSIBLE CAUSES. FUEL FILLER CAP LOOSE. PURGE SOLENOID VALVE IS DAMAGED OR HAS FAILED. CHARCOAL CANISTER IS LOADED WITH FUEL OR MOISTURE OR HAS FAILED. CANISTER DRAIN CUT VALVE CDCV IS DAMAGED OR LEAKING. FUEL TANK PRESSURE SENSOR IS DAMAGED OR HAS FAILED.CATCH TANK OR ROLLOVER VALVE IS DAMAGED OR FUEL TANK IS LEAKING. VAPOR LINES DAMAGED OR LEAKING BETWEEN THE PURGE SOLENOID AND INTAKE MANIFOLD PURGE SOLENOID AND CANISTER OR BETWEEN THE PRESSURE CONTROL VALVE.CHECK VALVE AND ROLLOVER VALVE. PCM HAS FAILED.

PO455- EVAP System
Gross Leak or No purge Flow

Gas Cap -Bad or just not on tight

Cracked Hoses
Purge Valve Stuck Closed
Canister Vent Solenoid Stuck Open
Fuel Tank Pressure Sensor

Check that gas cap is on, then after that
a repair shop

CODE PO455 IS EVAP SYSTEM LARGE LEAK 0.080 DETECTED. POSSIBLE CAUSES FUEL FILLER CAP LOOSE CROSS THREADED OR INCORRECT PART. PURGE SOLENOID VALVE IS DAMAGED OR HAS FAILED. CHARCOAL CANISTER IS LOADED WITH FUEL OR MOISTURE OR HAS FAILED. CANISTER DRAIN CUT VALVE CDCV IS DAMAGED OR LEAKING. FUEL TANK PRESSURE FTP SENSOR IS DAMAGED OR HAS FAILED. CATCH TANK OR ROLLOVER VALVE IS DAMAGED OR FUEL TANK IS LEAKING.VAPOR LINES DAMAGED OR LEAKING BETWEEN THE PURGE SOLENOID AND INTAKE MANIFOLD , PURGE SOLENOID AND CANISTER OR BETWEEN THE PRESSURE CONTROL VALVE, CHECK VALVE AND ROLLOVER VALVE. PCM HAS FAILED.

it sounds like you have a problem with the evap system which has to do with emissions for the fuel vapour system so raw fuel vapours won`t vent to the atmosphere and instead is drawn into and burnt by the motor.there is hoses,control valves,vent valves,canister,purge valves,gas cap, any one of these could be the problem.you will have to have the system tested at a shop to find the cause of the problem.

CODE PO455 - EVAP SYSTEM LARGE LEAK DETECTED CONDITIONS.POSSIBLE CAUSES FUEL CAP LOOSE MISSING,FUEL TANK FULLER NECK OR FUEL SENDING UNIT O - RING IS LEAKING, FUEL TANK PRESSURE SENSOR IS DAMAGED,FUEL TANK VAPOR LINES,CLOGGED,DAMAGED,OR DISCONNECTED,PURGE VALVE VAPOR LINE IS CLOGGED,DAMAGED,OR DISCONNECTED,PURGE SOLENOID IS NOT OPENING,IT MAY BE DAMAGED OR STICKING,VENT SOLENOID IS NOT CLOSING,MAY BE DAMAGED OR STICKING,PCM HAS FAILED.

Mitsubishi 2006 faulty fuel cap, leaking vent or purge solenoid, EVAP hose faulty or leak on fuel tank.... replace the fuel cap and a week later the light was back on...the code is P0442..what to do next

CODE PO455 EVAPORATIVE EMISSION SYSTEM LARGE LEAK DETECTED.POSSIBLE CAUSES CANISTER VENT SOLENOID MAY BE STUCK IN OPEN POSITION / EVAP CANISTER TUBE EVAP CANISTER PURGE OUTLET TUBE OR EVAP RETURN TUBE DISCONNECTED OR CRACKED OR CANISTER IS DAMAGED / EVAP CANISTER PURGE VALVE STUCK CLOSED OR CANISTER DAMAGED / FUEL FILLER CAP MISSING LOOSE NOT TIGHT OR THE WRONG PART / FUEL VAPOR HOSES TUBES BLOCKED OR RESTRICED OR FUEL VAPOR CONTROL VALVE TUBE OR FUEL VAPOR VENT VALVE ASSEMBLY BLOCKED /FUEL TANK PRESSURE SENSOR HAS FAILED MECHANICAL FAULT /FUEL TANK CONTROL VALVE IS CONTAMINATED DAMAGED OR HAS FAILED.