EVAP emissions/"CHECK ENGINE" problem

[trouter]

Hello!My 2000 Camry LE 2.2 4 cyl with about 125,000 miles on it is giving me the following OBD-II codes.It has set PO441f and PO446.It has pending codes PO440,PO441 and Po446.Before I start tracing vacuum lines and wiring,does anybody have any suggestions?The set code PO441f refers to "Evaporative emission incorrect purge flow" .This sounds like either a vacuum leak of some kind or a faulty solenoid.The other set code, PO446,refers to "evap vent control circuit".This sounds electrical.Of the 3 pending codes,PO441,minus the "f", and PO446 are repeats but the new pending PO440 refers to "Evap emission control sistem.I did remove the air filter housing assembly a few weeks before the codes started popping up to clean out the lower housing of leaves,pine needles and other debris while I was replacing the air filter.I had to unclip several harnesses and vacuum lines from the filter box.Are any of the Evap related solenoids or vacuum lines attached to it?

[toyomoho]

The fuel tank emissions system (EVAP) has a leak.

The AutoZone website has very good information on the EVAP system and trouble codes.

http://www.autozone.com/shopping/rep...00c15280092659

[trouter]

Hi Toyomoho!I'm sorry that it has taken me so long to answer your response,but between the holidays,the weather and some other matters that came up I just haven't had any chance to.I am going to take a look at the autozone site in a few minutes.I understand that this group of codes indicates a problem with the evaporative emissions system,but i was just curious if that PO446 which uses the word "circuit" indicates a problem with the wiring as opposed to a physical leak?I hope not as I hate electrical problems!I just had to track down a broken wire that was causing the 2 brake lights located on the trunk lid not to work.
Trouter

[toyomoho]

The EVAP circuit meaning all parts, hoses, wiring within that circuit.

This circuit could include vacuum hoses, sensors, charcoal cannister, even the gas cap. There are a couple of elelctric solenoid valves to open/close vacuum hoses, a pressue sensor to monitor fuel tank and system pressure but no serious electronic circuits like a computer board, etc.

The codes attempt to narrow down the area but is are not part specific..

P0446: Evaporation Emission Control System Vent Control Malfunction.

The computer is detecting one of the below:

When the VSV for the vapor pressure sensor is off there is no continuity between the vapor pressure sensor and charcoal canister.

When the VSV for vapor pressure sensor is on there is no continuity between the vapor pressure sensor and gas tank.

Continuity means air flow. The various parts are connected with hoses.

Once the EVAP system has been purged the pressure in the canister is equal to the atmospheric pressure (the system has a leak). Hence the need for a very simple pressure sensor.

Items to check are a malfunctioning VSV valve (solenoid valve) for either the vapor pressure sensor or EVAP valve (another solenoid) and their wiring, bad vapor pressure sensor (same sensor as before), damaged or disconnected hoses, cracked canister, fuel tank overflow valve damaged (manual valve).

Suggest starting out by checking the vapor pressure VSV, this is the vacuum valve on the canister and the canister itself.

Overfilling the tank may lead to issues with the canister failing due to fuel.

Autozone may have the specific codes. Do a Google search on the code numbers plus the word Toyota. You should turn up a lot of interesting info and maybe a few drawings, etc.