Po441 insufficient purge flow changed both valves no change cap good, running ruff bad intake gasket did that wow runs good now still no change with code when the valves where changed lines looked good no charcoal and not wet with fuel where do i look now?

A check sometimes missed is a simple one. Check the fuel cap. Sounds silly but a loose or worn cap can alter the sensor readings on the EVAP system. Remove the cap and take a good look at the seals on the cap and in the hole it fits into. Even a small amount of wear or damage can trigger the error code.

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

yes this could be the problem. the mechanic may be on to something here

PO449-- Evap Vent Valve/Solenoid Circuit Malfunction

PO441--Evap Purge Valve Incorrect Flow
PO 443,444,445 Purge Control Valve Issues


There was no reason to change the gas cap or
purge control valve

Didn't Google the code & use it correctly to diagnose
the problem

Of coarse

Any Evap System code or failed component
will effect performance, as that is an unmetered
air source & the pcm will drive fuel trim rich from
a lean condition

NOPE CANT ERASE CODES UNTIL THE PROBLEM IS FIXED OR THE SERVICE ENGINE LIGHT SOON WILL STAY ON. CODE PO441 - EVAPORATIVE EMISSION EVAP SYSTEM INCORRECT FLOW DETECTED.CHECK INTAKE VACUUM HOSE CONNECTIONS AT THE EVAP CANISTER PURGE VALVE.IF ALL IS GOOD.THE EVAP CANISTER PURGE VALVE COULD BE BAD. CODE PO 442 - EVAPORATIVE EMISSION EVAP SYSTEM SMALL LEAK DETECTED. EVAPORATIVE EMISSION SYSTEM LARGE LEAK DETECTED FUEL CAP LOOSE OR OFF MISSING. CODE PO 446 - EVAPORATIVE EMISSION EVAP SYSTEM VENT CONTROL CIRCUIT MALFUNCTION.

Hi there osborne_shay,

Those codes refer to a problem with the drive train in your Avalon. Here is what the codes mean.


PO441-Evaporated Emission Control System / Incorrect Purge Flow
PO402-Excessive gas flow through the EGR valve

The cause for these issues are either that the components are faulty or they just need to be cleaned.

P0441 Evaporative Emission Control System Incorrect Purge Flow
OBD-II Trouble Code Technical Description

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
THIS IS LIKELY FROM TOPPING OFF THE TANK EACH TIME YOU FUEL UP



P0455 is similar:

Technical Description

Evaporative Emission Control System Leak Detected (no purge flow or large leak)
What does that mean?

This indicates a fuel vapor leak or lack of purge flow in the EVAP control system. It means a large leak has been detected. 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.
Symptoms

You likely won't notice any drivability problems.
Causes

A code p0455 most likely means one or more of the following has happened:

* A loose or improperly affixed gas cap
* A non-conforming gas cap (i.e. not factory/original brand)
* Other leak or damaged piece in EVAP system

Possible Solutions

With a p0455, the most common repair is to:

* Remove and reinstall the gas cap, have AutoZone clear the codes, and drive for a day and see if the codes come back.
* Otherwise, replace the gas cap, and/or
* Inspect the EVAP system for cuts/holes in tubes/hoses (you may hear a vacuum noise or smell fuel), repair if necessary

Thanks for using FixYa - a 4 THUMBS rating is appreciated for answering your FREE question.

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.

Look, that code means:
P0441 - Evap emission control system Incorrect purge flow

so try to replace the emission control.