Hey everyone,
MY engine light went off last night on my 01 Camry LE 4Cyl. I ran the codes and got P0440, P0441, and P0446, which I have the description and diagnostic procdures for. I'll check the gas cap tonight and check the engine for any loose connections, etc.

My question is, how serious can the problem(s) potentially be? Can I drive it around without damaging the car? I imagine since they're EVAP/Emissions issues, the car will work fine(just as itwas last night when the light went off, running fine)but just be bad for the environment, which at this point is fine with me and my wallet. Any help is appreciated.

Thanks, Kevin

 

Another piece of info.. I just got the car inspected for PA last week and it passed with flying colors on both the safety and emissions. What is the possibility that these errors could have been caused by something that was knocked off/loose, screwed up, broke during the inspection?

 

So we're dealing with EVAP system malfunction, EVAP Control system - incorrect purge flow, AND EVAP system - vent control malfunction (same as P0441).
Sigh...code 0440 and 0441 are fat ones with such large "problem areas".

You said you have the descriptions and things to check but i'll just list what i have for the sake of completeness.

0440
Vapor pressure sensor malfunction
Fuel tank cap cracked, damaged or incorrectly installed
Vacuum hose blocked, cracked, torn or disconnected
hose or tube blocked, cracked, torn or disconnected
Fuel tank damaged
Charcoal canister damaged.

0441
Open or short on VSV circuit for EVAP
VSV for EVAP
Open or short in vapor pressure sensor circuit
Vapor pressure sensor malfunction
Open or short in VSV circuit for vapor pressure sensor
Malfunction in VSV for vapor pressure circuit
Vacuum hose blocked, damaged or disconnected
Charcoal canister malfunction

I say go through with a flashlight and inspect as much as possible. If nothing seems to be the matter, reset the CEL and drive on it. If it reappears, get the new codes. If they're the same issues, call up your facility you brought your vehicle to last, and see what they say. If they are reputable, they should be willing to inspect for free.

If your gas cap is fine, i would check the area around the gas filler neck and tube to the gas tank. Some have reported that area rusting out, which of course would mean you're evaporating gas and loosing pressure. HOpefully with a 2001 a thing like that doesn't happen so early. And you'd probably notice very poor fuel economy.

It's not dangerous to drive with this CEL, just drive normally and at the first sign that your car isnt driving normally (besides poor fuel economy), pull right over, shut it off and call your tow company. If the CEL begins to FLASH, do the same thing, but it's much more urgent. However, when a CEL flashses, something has already broke...hahah...

Good luck.

 

Does the CEL change colors? I just got off the phone with the place that inspected it, trying to get them to do the diagnostic for free, since the coincidence of timing (they had the car just last week) is too perfect. I asked him if these codes are serious enough that I can't/shouldn't drive the car, and he said since the CEL light is yellow right now(yellowish/orange), that is fine, just not recommended, but if/when it changes to red, I should definitely pull over and stop driving immediately. This make sense?

 

In your camry the CEL does not change colors (not to my knowledge). Your cel is always going to be YellowOrange. The red he spoke of is the same as my comment about stop driving immediately if your CEL begins to flash.
When my engine blew my CEL was flashing
I'm sure you'll notice some failure (perhaps catastrophic like mine), before you even see the darn thing flash. hahaha.

Again your codes are not indicative of something dangerous, but of course its best to drive with no codes. Most of the time when you get EVAP codes, your car will simply run in a sort of default mode. Meaning the computer will just try to keep the car running, but the mixture of air and fuel for combustion may not be optimum (running lean or rich), as well as other systems are running in a more mindless manner.
Hopefully they'll check it out asap. =)

 

I checked the car out last night. No loose, disconnected hoses, vaccuum lines(though I wouldn't know what one looked like if it bit me), no rushing air or smells indicitive of a leak/disconnection somewhere. The gas cap was not on all the way it was on, just not on to the point of the clicking, probably been that way since the inspection 11 days ago.
The loose gas cap would only explain P0440 though, correct? That's not the solution for all 3 codes, right? I had the service center clear/reset the codes the other night, and the light has not come back on as of yet. Once it does, I'm planning on taking it back to the inspection station and getting them to diagnose the problem for free, since it was obviously their fault/doing that caused this.

 

loose gas cap can cause all sorts of evap codes. just wait and see. always make sure that cap clicks at least once when you fill up and double check to see the rubber oring hasnt degraded severely.

 

Ok, I will tell you about my experience with the P0441,P0446 Evap sys incorrrect flow during purge. I know from experience that there are 2 solenoids involved. The purge solenoid and the vent solenoid. First I checked the solenoid on the engine (purge). This one opens and allows vacuum to suck fuel vapors. If it is inop, might be the problem. I took the hose off of it, started the car and checked for vacuum. None. I applied battery voltage across the 2 terminals and then had vacuum. Therefore purge solenoid is good. Vent solenoid (VSV) is under the car on the charcoal canister mounted up above the rear axle area. If you can manage it, jump batt voltage to it. (I have even seen someone use a 9V square battery) and see if it clicks on and off. Or...take the gamble and change just the solenoid like I did. You can get them on the web for all different prices from 25.00 to 100.00+ Where this solenoid is located it is exposed to all types of weather and road salt. The purge solenoid is on top of the engine so it is more or less warm and dry all the time. Good luck all

 

Technical Description

Evaporative Emission Control System Malfunction
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.
Symptoms

You likely won't notice any drivability problems.
Causes

A code P0440 could mean one or more of the following has happened:

• The gas cap is not installed or working properly
• The purge solenoid has failed
• The canister is plugged and not working properly

Possible Solutions

With a P0440 OBD-II trouble code, diagnosis can be tricky at times. Here are some things to try:

• Remove and reinstall the gas cap, clear the code, and drive for a day and see if the codes come back.
• Inspect the EVAP system for cuts/holes in tubes/hoses
• Inspect for damaged or disconnected hoses around the Evap purge solenoid
• Check and/or replace the sensor
• Check and/or replace the purge valve
• Have a professional use a smoke machine to detect leaks

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

P0446 Evaporative Emmission Control System Vent Control Circuit

OBD-II Trouble Code Technical Description

Evaporative Emission Control System Vent Control Circuit Malfunction
What does that mean?

Evap vent valve has only one purpose. It closes in order to seal the vent so the EVAP system can pressurize and ensure there are no leaks. Evap vent valve is usually supplied Batt. voltage with key on. The ECM's driver controls the ground, and when grounded, activates the valve (closing it). If the ECM detects a short to ground, and open,or a short to battery voltage on the control circuit, P0446 will set. Code also may refer to ECM detecting that EVAP system is unable to achieve or maintain vacuum during test.
Symptoms

There will be no obvious symptoms to driver, other than MIL illumination.
Causes

A code P0446 could mean one or more of the following has happened:

• Faulty vent valve
• Open, short or excessive resistance on Vent valve control circuit
• Blockage of vent valve
• Bad PCM

Possible Solutions

With a P0446 OBD-II trouble code, here are some things to try:

• Replace Vent valve
• Repair open, short, or resistance problem in control circuit
• Repair open, or short, or resistance problem in power circuit
• Replace PCM

thats' the big science behind the codes. otherwise, replace fuel tank cap, remove ECU fuse to reset codes, or do it at any parts store with scanner, and IMMEDIATELY run a can of Seafoam through tank of gas, preferably, doing 70 on frwy for about 30 minutes at least. CLEANS EVERYTHING very well.

 

I have the same codes and think I found the problem. It appears that one of the wires (yellow) connected to the purge valve is broken. I tried to remove the connector so that I could fix the wire. No luck in removing the connector. Anybody know the trick? I looked for a release of some sort but can't seem to find it.