Check Engine - Evap Emission Control P0440 & P0446
Thread Starter
Instructor
Joined: Jan 2010
Posts: 817
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From: NY
Check Engine - Evap Emission Control P0440 & P0446
Hello friends,
I have a 130K+ 2002 SC430 in which I recently started to smell gas in the cabin when air vents were set to pull air from outside. Within two weeks, I got the check engine light with two codes, P0440 and P0446, which mean "Evap Emission Control System Malfunction".
In doing some reasearch the check light light could be everything from a gas cap which is not tighened properly, to a bad "charcoal canister " (whatever exactly that is), to a cracked or disconnected "Evap Hose". The only other SC430 related thread I could find on this topic is https://www.clublexus.com/forums/sc-...0440-cels.html
I'm really hoping this is not very serious. If it factrors in, I only use 93 octane gas. Interestingly enough, the check engine light came on within 30 seconds of me using the window washer to clean the windshield (at highway speeds), likely a coincidence.
Any thoughts are very much welcome, thank you.
I have a 130K+ 2002 SC430 in which I recently started to smell gas in the cabin when air vents were set to pull air from outside. Within two weeks, I got the check engine light with two codes, P0440 and P0446, which mean "Evap Emission Control System Malfunction".
In doing some reasearch the check light light could be everything from a gas cap which is not tighened properly, to a bad "charcoal canister " (whatever exactly that is), to a cracked or disconnected "Evap Hose". The only other SC430 related thread I could find on this topic is https://www.clublexus.com/forums/sc-...0440-cels.html
I'm really hoping this is not very serious. If it factrors in, I only use 93 octane gas. Interestingly enough, the check engine light came on within 30 seconds of me using the window washer to clean the windshield (at highway speeds), likely a coincidence.
Any thoughts are very much welcome, thank you.
Last edited by jasone36; Feb 18, 2012 at 04:38 PM.
Racer
Joined: Feb 2007
Posts: 1,637
Likes: 60
From: DC
Help us help you -- as indicated in the other thread:
Try that and tell us where the smell is most noticeable. Also:
Do you often "top off" when filling with gas (i.e. squeeze a more gas into the tank after the pump first turns off?
Also:
My bet is on the charcoal cannister.
Let people help you by providing more information. Remember the forum motto: "If you're not happy, we're not happy."
Also:
Let people help you by providing more information. Remember the forum motto: "If you're not happy, we're not happy."
Thread Starter
Instructor
Joined: Jan 2010
Posts: 817
Likes: 21
From: NY
JohnnyCake, thank you for your response. The very next time I smell gas in the cabin I will definately sniff around the front and then rear of the car and provide information back to this thread. I have been riding for a day with the vents set to grab air from the outside and haven't had the smell during this one day yet, but will continue to "sniff around".
The state I fill up in has full service gas pumps, meaning most of the time I don't have the opportunity to pump the gas myself. It is possible that the gas attentands "top off" the gas tank, I will now keep a close eye on this to make sure it does not happen. I do always use 93 octane premium gas.
Thanks again JohnnyCake, and if anyone else can chime in I would appreciate it.
The state I fill up in has full service gas pumps, meaning most of the time I don't have the opportunity to pump the gas myself. It is possible that the gas attentands "top off" the gas tank, I will now keep a close eye on this to make sure it does not happen. I do always use 93 octane premium gas.
Thanks again JohnnyCake, and if anyone else can chime in I would appreciate it.
I had this happened with my 2001 LS430, since I work in a Toyota dealership, I had my mechanic looked at and was told that the canister needed to be replaced. This was after all the chasing around trying to find any and all leaks along the fuel line AND put on a new gas cap. I hate to tell you any bad news but the canister will be my bet as well.
By the way, I sold the LS and got an SC430, that is why I am here with all you guys now.
By the way, I sold the LS and got an SC430, that is why I am here with all you guys now.
I did have the gas smell, and yes, it's the same code. My mechanic told me to start small so I first change the gas cap. It came back. We traced the fuel line and replaced some L connectors and T connectors. It came back again. So it's to the canister next. I put it off for a couple of month and decided to just cleared the code and traded for this SC430 that we took in as a trade. The old car needed new tires and the air suspension were going out on me.
The canister IS big bucks labor was like 4 hours for the LS. Don't know about the SC.
The canister IS big bucks labor was like 4 hours for the LS. Don't know about the SC.
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Driver School Candidate
Joined: Feb 2009
Posts: 47
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From: CA
Jason. I just went through these exact codes last year. It ended up being a disconnected evap hose. Its the hose that is near the oil fill under the hood. Take the engine cover off and take a look at the evap hose there and make certain it is connected. Hope thats all it is. Here is a link that helped me find it. If you scroll down Talwang posted a great picture of the notorious hose that pops off...
https://www.clublexus.com/forums/sc-...t-on-crap.html
https://www.clublexus.com/forums/sc-...t-on-crap.html
Last edited by Swishh; Feb 18, 2012 at 10:37 PM.
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Lead Lap
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From: Iowa
First I would make sure that the car is not being over-filled and maybe the charcoal cannister will dry out a bit over time as it goes through its normal pressurize and purge functions (to burn gas fumes that accumulate in the tank that in the old days were simply vented to the atmosphere). Agree with checking the lines in the engine compartment suggested in the earlier post. The clamps don't hold them very tight. Also, regarding the cannister, there are valves and vents mounted into it, and so it may not be the cannister per se, but one of those components. Hard to get to (have to drop part of the rear suspension) and so I think that most places just replace the entire assembly. There are diagnostic procedures (posted here - see older threads) that Lexus/Toyota can follow that will isolate which part of the system is failing, but it's cheaper to check the easy stuff first.
Although it has nothing to do with your problem, if you have a choice between 91 octane and 93 octane, you are probably fine with 91. Mine doesn't pre-detonate with 89, although I opt for 91 most of the time.
Although it has nothing to do with your problem, if you have a choice between 91 octane and 93 octane, you are probably fine with 91. Mine doesn't pre-detonate with 89, although I opt for 91 most of the time.
Last edited by kjcole; Feb 19, 2012 at 06:01 AM.
I have a RX300 that my daughter drives at college that has had the same codes for some time. She admitted that she was topping off the tank. I replaced and inspected everything I could and finally just decided to ignore it. It took about 4 months, but the CEL went off about 3 weeks ago. I was aware of the issue with the charcoal canister and decided to see if it might dry out. There is no way to prove anything at this point, but I do suspect the canister had some liquid gas in it and eventually dried out. I know that the emissions test runs more frequently than 3 weeks so it seems it cleared itself. I have my fingers crossed at this point.
Thread Starter
Instructor
Joined: Jan 2010
Posts: 817
Likes: 21
From: NY
Friends,
With the help of this forum and thread I looked under the hood and indeed found that what appears to be the exhaust evap hose was disconnected (it must have become disloged over time and the metal "clip" seemed loose).
In the attached picture, you can see the hose which has the green marking was going nowhere... the part where it is supposed to be connected is underneath (not very visible in picture). I reconnected it and I am now on a mission to tighten and/or replace the metal clip which is supposed to keep the evap hose from getting disconnected.
Interestingly enough, before this forum pointed me in the direction of the hose I have noticed that my car was making a rather loud clicking sound from the part of the engine where the disconnected hose was... but I initially didn't make the corellation.
I have reset the check engine light and I'll watch it closely. I have also retightened the gas cap, just in case. I am really hoping it is not the charcoal canaster like others have posted.
Thanks again everyone and I am cautously optimistic.
With the help of this forum and thread I looked under the hood and indeed found that what appears to be the exhaust evap hose was disconnected (it must have become disloged over time and the metal "clip" seemed loose).
In the attached picture, you can see the hose which has the green marking was going nowhere... the part where it is supposed to be connected is underneath (not very visible in picture). I reconnected it and I am now on a mission to tighten and/or replace the metal clip which is supposed to keep the evap hose from getting disconnected.
Interestingly enough, before this forum pointed me in the direction of the hose I have noticed that my car was making a rather loud clicking sound from the part of the engine where the disconnected hose was... but I initially didn't make the corellation.
I have reset the check engine light and I'll watch it closely. I have also retightened the gas cap, just in case. I am really hoping it is not the charcoal canaster like others have posted.
Thanks again everyone and I am cautously optimistic.
Thread Starter
Instructor
Joined: Jan 2010
Posts: 817
Likes: 21
From: NY
I have decided to also replace the "clamp" which holds the hose in place. It seems like a good replacement clamp which fits is AutoCraft AC5202V (4 1/4" - 4 5/8"). Available at your favorite car parts store.
It comes in a 4-pack, so I will also replace the other easily accessible clamps which hold hoses in the same area.
It comes in a 4-pack, so I will also replace the other easily accessible clamps which hold hoses in the same area.
Thread Starter
Instructor
Joined: Jan 2010
Posts: 817
Likes: 21
From: NY
UPDATE:
Six weeks after the fix I explained above, the evap cable for disconnected again (I started smelling gas in the car again). I have now decided to replace the motor mounts along with the transmission mount which are most certainly causing the evap cable to disconnect. The mounts are under $70 each at Sewell Lexus online.
See my other thread on this item here: https://www.clublexus.com/forums/sc-...n-diagram.html
Six weeks after the fix I explained above, the evap cable for disconnected again (I started smelling gas in the car again). I have now decided to replace the motor mounts along with the transmission mount which are most certainly causing the evap cable to disconnect. The mounts are under $70 each at Sewell Lexus online.
See my other thread on this item here: https://www.clublexus.com/forums/sc-...n-diagram.html
