SHY820424

Hi all,

When I was driving my RX300 today, I noticed a check engine light come on.
I quickly went to bodyshop (Which was closed due to holiday) then stopped by at the advanced autoparts.
They were able to run the scan and gave me 3 codes:

P0440 : Evap Emission
control system malfunction

P0441 : Evap Emission
control system malfunction
purge flow fault

P0446 : Evap Emission
control system malfunction
Vent circuit malfunction

The guy told me that replacing oil cap could help us, so we replaced them for $6.00, yet the light is still on.

Is this something we need to worry about??
Can we drive this vehicle until Wednesday, when my bodyshop open again??

Please let me know where I can start or what needs to be replaced.

Thank you all

19psi

the light won't turn off until it is reset with a scan tool; even if it the problem were to be repaired.

the car will run fine. there is actually no engine problem. it's simply a matter of the emissions evap system having a problem. basically, the system that traps fuel vapors from the tank and recycles it into the engine has a fault.
it has nothing to do with engine performance.
you could drive it forever and never notice a problem except hte light will remain on.

if you want it repaired, you'll have to go to the dealer, as MOST private shops don't have the necessary equipment and evap system diagrams to diagnose and repair this fault.

salimshah

We will have to wait for some one to post possible reason to get the code you got. By description it seems that your FUEL cap was not on properly.

With helpful folks here, I recommend that people post the code here and wait for the good advice.

Salim

carguy07

Gas cap is easiest to check, then per mikey00 "These are the 3 codes you get when the evap hose is disconnected behind the air filter box."

https://www.clublexus.com/forums/sho...d.php?t=278195

Have you replaced the air filter recently?

May be helpful: https://www.clublexus.com/forums/att...4&d=1127099390

BCP43002

You can disconnect the battery neg cable for a few minutes to reset the light. Once it is reset see if it lights back up again when you drive around. Look at this link for possible solutions https://www.clublexus.com/forums/sho...d.php?t=323956

SHY820424

Thank you all for the valuable information.
I hope something as simple as replacing gas cap could make this go away.
But I just wanted to be sure that it would be okay for me to drive this car around..would it be okay??
It seems like the car is running fine, and I really can't detect any problems..
Would it be safe for me to drive say...about 30 miles/day?

Thanks all and....

HAPPY NEW YEAR!!!!!!!!!

carguy07

No worries, you can keep driving with no damage. The worst thing that you have is a vacuum leak and some gas fumes venting.

I would take the gas cap off and put it back on to make sure you have a good seal. Disconnect the battery to reset the light, while your up there look around for loose or damaged hoses by the air filter box.

Lil4X

When you remove the gas cap, check the rubber rim to be sure it is intact. When you reinstall (not necessary to "replace" it) the cap, be sure to turn it until it clicks TWICE (I think I remember this correctly). It is amazing to me that an improperly seated gas cap can throw a CEL, but it does happen.

As others have noted, that hose below the air filter box if jostled loose during filter replacement can also throw an emissions code too.

Meanwhile enjoy your car and don't worry about those codes. They are worth looking into, but are not critical to the preservation of your engine.

Lexmex

As mentioned above, usually it is the gas cap, hose on the back of the air box, an evap sensor, one of the rubber hoses on the evap system with a leak or the charcoal canister on the rear of the vehicle. If I were there I could diagnose this further and track it down, but this needs either a competent mechanic or a trip to the toyota/lexus dealer to track down which part is via use of a more advanced scanner.

I concur with my colleagues that you are free to drive until you can take it into the shop.

For now, I will show some photos of possible areas to check out.

Lexmex

The area in blue is where the charcoal canister is and this can be a trouble area, but have the mechanic check the hoses coming out of this area and in the zone where the red arrow is where there are some valves that also should be checked out.

Lexmex

All the hoses in this area should be checked for leaks and that they are well connected.

Lexmex

Just to the right of that area (and I don't have a photo) is the black airbox, and on the back of it there is a hose that connects to it. Check to see that it is connected and there are no cracks on the hose that could cause a leak.

SHY820424

Thanks a lot to all.

From all the information I have gathered, it could be something as simple as replacing the gas cap. I did replace them,yet did not reset the battery so I can take it to the bodyshop as they promised me to look over my car.

I think when we went in for the trans check up, they changed the trans fluids as well as trans filter. Could this have been a cause as well?? something was loose on trans filter??

Again, thanx to all and I'll take some information I have gathered here to the bodyshop tomorrow.

Happy 2008!!!

Lexmex

Transmission fluid and filter and their changeout would be independent from that.