DshngDaryl

I have had a P0442 error for a couple of months. This is read as a Small Emissions Leak.

I tried the most common solution, which is replace the broken vaccum hose under the engine cover near the Dipstick (The hose was broken)

Then I tried the second most common problem which is replacing the gas cap with a OEM one.

Then I tried the third most common solution which is sanding off any rust you find in the filler neck.

I think it might be the dreaded Charcoal Canister solenoid, but wanted to run the symtpoms by you for a second/third/fourth/fifth opinion.

I think it is the Charcoal Canister Solenoid because I smell gas when ever I take the cap off to fill up. I think those vapors are suppose to be sucked into the engine and burned off. When the hose was borken I did not smell the fumes/Vapors/Smell because they were leaking out the broken hose.

Also there is never any pressure in the tank, so I don't think a vaccum is being applied. My theory is the solenoid isn't opening and thus no pressurization which throws a P0442.

So if it is the related to the solenoid, does anyone have any ideas what I should check? Fuse? Connection? Common Leak in the canister?

Does anyone have any first hand experience or other theorys they want to send my way?

Bgw70

Did you look very closely for a second broken hose?
check again, if one cracked then more hoses may be in the same condition.

DshngDaryl

Good thought! - I did look for another broken hose, but didn't look "that hard." (I looked for an obviously broken hose, not a pin hole leak) I am trying to talk my friend into doing a smoke test on my car but haven't heard back from him.

Hopefully it will be a hose, though it seems the vapors would dissipate if it was.

Bgw70

Check out this link...now keep in mind it is for a Sienna but most Toyota systems are similar if not the same. This guy has some good ideas. http://www.findonefindall.com/toyota...evap_P0446.htm

if it was earlier, I would snap some pics from the Lexus Maintenance manual...let me know if you want those steps.

DshngDaryl

Hey BGW thanks for the link. I agree with you, even though the parts have different numbers, most Toyta/Lexus systems are based on the same principles, and the theories are interchangeable.

Reading the psot, it dawned on me I only have a P0442 code. It seems like if one of my valve weren't working, then I would get other codes. I assume the ECM would not see an electrical drop in the system and tell me a valve was not working.

I will have to ponder this further (and rescan my system to see if there are any other codes)

I also found this article http://repairpal.com/OBD-II-Code-P0442 It says I should read my fuel tank pressure using my scan tool. If the pressure is low, then I guess I could verify a leak. Anyone know what the "Ballpark" pressure should be?

Bgw70

Here is the Lexus procedure...the pages might end up out of order.
warning to all owners, when filling the car with gas, stop filling when it clicks. If you keep clicking and overfill, you stand the chance of putting raw gas in the charcoal canister and you will ruin it...very expensive.

DshngDaryl

WOW BGW! That is FANTASTIC! THANK YOU so much! I am most appreciative

mandyfig

So nice of you to spend the time to show us. Thank you Bgw70!

DshngDaryl

Once again you are right BGW. I was looking over the engine to get a better sense of my starter problem when I found a cracked hose.

75 cents later I had a foot of 1/4 inch vacuum hose and the problem fixed (at least according to the pressure test from my Car Software)

Bgw70

That is fantastic news!!!
now if you can only get the starter working again... :-(

HardTimes

Sorry to dig up an old thread, but was hoping since it was on this topic, that it would be more appropriate than starting a new thread. Anyway ....

Have been getting recurring small emissions leak codes as have many others with this vehicle. Things I have done so far ....
1 - replaced gas cap
2 - checked hoses for cracks (photos later with follow-up question)
3 - replaced motor mounts (had about 4-5 inches of throw when throttle applied with brake on and applying throttle!! - I assume this was excessive as I have only about an inch now)
4 - applied numerous spring clamps around hose joints to try to prevent leaks there

Questions:
Anyone else add clamps in attempt to prevent disconnections? Here is some photos showing some areas where I've "modified" - not sure if that counts as a mod or not
Hose clamp circled was added to secure a very loose hose? Normally very loose? Or could this even trip the P0442 code?
The hose between the red arrows seems dry and non-pliable. Is this just a regular vacuum hose? Or does it need to be replaced with a specific type of hose?
This arrow indicated hose seems to keep coming loose despite the added hose clamp. I do like to do the WOT thing from time to time, but I would think the design should allow for that. Anyone find a fix for this? Do these look like OEM hoses? If not, could this be part of my problem?Sorry for the lengthy post, but I've read many posts about these emissions DTCs and haven't seen these addressed specifically. I've seen where people have talked numerous times about the hoses near the green service port, but have not addressed how to keep it connected.

Also, thinking this may help someone else out as it would appear many have these DTCs pop-up. These are some of the things I'm trying to eliminate the codes.

Bgw70

that hose in the last picture does not look correct...it looks like fuel hose or something like it...I had the code the other day and that was the first time in a very long time. That hose came off. I only have the small OEM clamps.
if I were you, I would replace the hose with vacuum line hose and make sure it is long enough and has some flexibility...then you have your problem solved. You said your motor mounts were good, so no issue there.

Coleroad

I can see multiple hoses with cracked ends. This definitely shows they are brittle. Vacuum hoses are not expensive, just buy bulk and replace. It looks like someone already had a hayday in there.

Coleroad

exactly, that hose is to large of a diameter too. Would be almost impossible to get to seal tight. Screw those clamps to tight and you'll break the plastic nipples too.

DshngDaryl

I remember when I had this problem. I thought it might be a charcoal canister and was worried about the overall expense. So I tried to save as much $$$ as I could and fixing my problem with about $5 of generic vacuum hose and some clamps.

This is a pretty easy problem to solve and can be done by most people.

I first tried replacing the obviously broken hose and resetting the code, which worked for a day or so. Then it came back. I inadvertently thought I had exhausted that solution. It turns out that hoses decay at the same rate and if one is bad, the rest will follow, especially after the hoses you fix put more pressure on the old ones.

I ended up replacing all the hoses and resolving my problem.

If I were to do it again, I would buy the OEM hoses from Lexus. Some of those hoses have weird angles to avoid other components. Some of the generic hose I got was either SLIGHTLY too narrow or SLIGHTLY too fat. I think 1/4 inch hose worked the best but not perfect.

The OEM hoses are more expensive than generic hose, but it would have saved me a bunch of frustration when I was replacing the Vacuum hoses on the power steering solenoid. Plus if people look at your engine, OEM hoses give it a more finished look and not that "Slapped together appearance"