Have a 2003 hyundai elantra gls has code po441 I've replaced the o2 sensor twice and some bad fuel lines the purge valve and canister have been replaced to but still saying po441

Arrow would indicate direction of flow and flow is from the canister to the intake.

po421 catalytic converter code [warm up catalyst efficiency below threshold bank 1] means the o2 sensor is detecting low oxygen in exhaust problem can be cat conv going bad---o2 sensor faulty-and or bad spark plug ....as to the p0441 evap system[-evap emissions control system incorrect purge flow ] this is a system code meaning any part of the evap can have problem will need to check the fuel lines vapor lines for damage or breaks-check purge valve -purge valve solenoid- canister- and vacuum lines

Most likely is a bad EVAP purge valve. But check below list.
This indicates that a part of the EVAP control system is no longer functioning correctly. The EVAP system consists of many parts, including (but not limited to) the gas cap, fuel lines, carbon canister, purge valve, and other hoses. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.

EVAP emission canister purge is controlled by a valve which allows engine vacuum to pull stored fuel vapors from fuel tank into the engine to be burned, rather than be vented to atmosphere. A vacuum switch is used to detect when flow exists. If the PCM commands purge and sees that the switch is closed (indicating no detected purge flow) P0441 is set.
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Likely, no symptoms will be discernible to the driver, other than the illuminated Check Engine Light.
Causes

A code P0441 could mean one or more of the following has happened:

• Bad vacuum switch
• Broken or damaged EVAP line or canister
• Open in PCM purge command circuit
• Open or short in Voltage feed circuit to Purge Solenoid
• Faulty purge solenoid
• Restriction in EVAP solenoid, line or canister
• Corrosion or resistance in purge connector
• Bad PCM

Possible Solutions

With a P0441 OBD-II trouble code, diagnosis can be tricky at times. Here are some things to try:

• Replace Leak Detection Pump / LDP
• Repair damaged EVAP lines or canister
• Repair open or short in voltage feed circuit to Purge Solenoid
• Repair open in PCM purge command circuit
• Replace purge Solenoid
• Replace vacuum switch
• Repair restriction in Evap line or canister or solenoid
• Repair resistance in purge connector
• Replace PCM

po133 is the o2 sensor and the po441 is a Evap Emission Control System Purge Flow Fault

make sure you have vacuum at the intake port and also check the rubber hoses on the EVAP system

This indicates that a part of the EVAP control system is no longer fuctioning correctly. The EVAP system consists of many parts, including (but not limited to) the gas cap, fuel lines, carbon canister, purge valve, and other hoses. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.

EVAP emission canister purge is contolled by a valve which allows engine vacuum to pull stored fuel vapors from fuel tank into the engine to be burned, rather than be vented to atmosphere. A vacuum switch is used to detect when flow exists. If the PCM commands purge and sees that the switch is closed (indicating no detected purge flow) P0441 is set.

Causes: A code P0441 could mean one or more of the following has happened:
Bad vacuum switch
Broken or damaged EVAP line or canister
Open in PCM purge command circuit
Open or short in Voltage feed circuit to Purge Solenoid
Faulty purge solenoid
Restriction in EVAP solenoid, line or canister
Corrosion or resistance in purge connector
Bad PCM

Possible Solutions: with a P0441 OBD-II trouble code, diagnosis can be tricky at times. Here are some things to try:
Common Chrysler fix - Replace Leak Detection Pump / LDP
Repair damaged EVAP lines or canister
Repair open or short in voltage feed circuit to Purge Solenoid
Repair open in PCM purge command circuit
Replace purge Solenoid
Replace vacuum switch
Repair restriction in Evap line or canister or soleniod
Repair resistance in purge connector
Replace PCM

Hope this helps.

No, Each item has its own code more or less. A bad purge valve may give you a warning that the Evap system has a problem and this would include lines, tank, and the fuelcap. Sometimes the Code would be more specific naming the canister purge valve separately without including the lines, tank, or the fuelcap.

But the purge valve and the O2 sensors are completely different systems. The O2 sensors go on the exhaust and the purge valve is grouped with the fueltank. The comparision of the difference is like the purge valve belongs with the fueltank group and the O2 sensors belong with engine controls after the fuel system has finished its job.

I hope my solution is very helpful in explaining how each system is separate.

DTC P0441 - Evaporative Emission Control System Incorrect Purge Flow

What does that mean?
This indicates that a part of the EVAP control system is no longer fuctioning correctly. The EVAP system consists of many parts, including (but not limited to) the gas cap, fuel lines, carbon canister, purge valve, and other hoses. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.

EVAP emission canister purge is contolled by a valve which allows engine vacuum to pull stored fuel vapors from fuel tank into the engine to be burned, rather than be vented to atmosphere. A vacuum switch is used to detect when flow exists. If the PCM commands purge and sees that the switch is closed (indicating no detected purge flow) P0441 is set.

Symptoms
Likely, no symptoms will be discernible to the driver, other than the illuminated Check Engine Light.

Causes
A code P0441 could mean one or more of the following has happened:
* Bad vacuum switch
* Broken or damaged EVAP line or canister
* Open in PCM purge command circuit
* Open or short in Voltage feed circuit to Purge Solenoid
* Faulty purge solenoid
* Restriction in EVAP solenoid, line or canister
* Corrosion or resistance in purge connector
* Bad PCM

Possible Solutions
With a P0441 OBD-II trouble code, diagnosis can be tricky at times. Here are some things to try:

* Common Chrysler fix - Replace Leak Detection Pump / LDP
* Repair damaged EVAP lines or canister
* Repair open or short in voltage feed circuit to Purge Solenoid
* Repair open in PCM purge command circuit
* Replace purge Solenoid
* Replace vacuum switch
* Repair restriction in Evap line or canister or soleniod
* Repair resistance in purge connector
* Replace PCM

Other EVAP DTCs: P0440 - P0441 - P0442 - P0443 - P0446 - P0453 - P0455 - P0456

Hope helps.

Did you use a aftermarket O2 sensor or a genuine Hyundai one? If it's an aftermarket one it may be bad or not as good as the OEM one. See here for more details and other potential causes: P0133

P1166 O2 Sensor - controller adaption diagnosis malfunction (bank 1).

Trouble area:

* P1166 is case for HO2S (Bank 1, Sensor 1) Signal line open
* Fuel system (Fuel tank/Pressure regulator/Fuel pump/PSV) failure
* Poor connection to fuel line hose/sealing/cut
* Sealing between purge valve and fuel tank
* Air leakage in exhaust system
* Ignition system (ignition coil, spark plug, cable) failure
* Surge tank and intake port failure