Emissions
 

My 2001 Camry has had recurring Check Engine light coming on. I replaced the purge valve near the intake, turned off the light and drove it about 3 weeks with no issue. This morning I when I went to work, the light was back on. The codes my reader shows are PO441 & PO446, both having to do with purge flow. Can anyone offer any suggestions as to what I should do to fix the problem?

V6 or 4 cylinder?

Here is the list of possible issues.
Open or short in VSV circuit for EVAPOpen or short in VSV circuit for vapor pressure sensor
VSV for EVAP
VSV for vapor pressure sensor
Vapor pressure sensor
Charcoal canister cracks, holed or damaged

I have replaced the vacuum switching valve and the vapor pressure sensor. I replaced the cannister about 7 years ago with a factory replacement.. Is the valve in the side of the air cleaner a purge valve or the EVAP vent valve solenoid as I possibly put the wrong valve in since they look the same in the parts book. I am led to believe they may look the same but function differently. Is this correct? The under hood diagram refers to an Evap OBD Canister Closed Valve and labeled ACL. Is this the valve I am referring to in the air cleaner? Other than the Check Engine light, the car runs great, no misfire or loss of power. I need to get it repaired so I can get it smogged. Please help.

V-6 or 4 cylinder engine?

4 cyl

DTCs P0441 and P0446 are set when there is air leak in the emission vapor canister and components included with it, VSV for EVAP components and hoses, vapor pressure sensor and hoses, EVAP hoses to the gas tank or leaking fuel tank over pressure valve on top of tank. Or there issue with the EVAP sensor or ECU.The computer is recording the pressure inside the canister is the same as atmospheric pressure when it should not be. This could also be due to a bad vapor pressure sensor sending a bad signal or a bad ECU.

Might be a bad gas cap but it’s not listed.

Typically the canister body cracks.

Make sure the new VSV is really physically closed as a new valve can leak due to a defect. The VSV is near the air cleaner box.

A shop would do a smoke test. This test injects smoke from heated mineral oil (white smoke) into the EVAP system and one looks for leaks. However this is not always successful in finding leaks. One can make their own smoke generator on the cheap. YouTube has videos of how to build one.

Check for cracked hoses, cracked canister body.

If you need to fix it ASAP Toyota has a website where for $20 one can download service info. Toyota service info does have a procedure to follow for these codes.

https://techinfo.toyota.com/techInfo...a.com%3A443%2F
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