So I got a P0440 code a few days ago. Purchased a new OEM gas cap from Lexus, checked the vacuum hoses, cleared the code and drove the car. All was fine over the weekend until today. Same code. Any ideas on other areas to check? I remember when I got a P0440 and P0446 with my 1999 GS400 it was the charcoal canister. However, this is just the one code. Thanks!

 

I think you may have a cracked hose...use an inspection mirror and look at the bottom and backside of each hose.
or pull each hose and look it over.

it could also be the vacuum purge valve or the PCV.
have you ever changed the PCV?
the purge valve can be checked with 12v from the battery applied directly to the valve. If you hear it click then you are probably okay.

 

Thanks Bgw70, I've never changed the PCV. I'll check the hoses tonight and keep you posted!

 

Well I took the engine cover off and found a cracked hose! When I went to pull it off, it cracked even further. It was very brittle. So I guess the SC430 is not going anywhere until I can run by the AutoZone and get a replacement. Which will be today or tomorrow since we taking the car to the beach this weekend!!!

 

Thanks for sharing the pics and the information on your issue and possible solution. That's part of what makes this forum such a great asset to SC430 owners.

 

You could also just wrap the hose with electric tape or that melding type tape to check to see if code goes off. You may need to reset odb

 

The sealing tape is a good temporary option.

 

So glad you found the simple solution!

Just be ready for more vacuum lines to go bad.

I replace them as they crack or break with new lines I ordered on eBay.

when I had my P0440 and P0446 codes, I replaced the gas cap first because I missed the crack in the line. it was on the bottom and hard to see. That is why the lines should be removed...if they fall apart, it was time to replace.

purchase several feet to have some extra when it happens again.

 

Thanks! Yeah it looks like the previous owner had some lines replaced because some look newer than others. I'll keep some extra line around like you mentioned just in case!! Now to find the size of the hose....looks like 1/4"?

 

Ok, got the new line installed and took the car for a long drive...no CEL so far. The real test will be tomorrow because we're headed to the beach 2hrs away. Will post again when I return. Thanks for all the help!!

 

I bet the check engine light stays off which will make your day at the beach more Enjoyable!!!

have fun!

 

I'm happy to report no CEL! Woohoo!! 120 or so miles so I think that fixed it. Thanks!!!

 

So my better half brought the car home today and said the CEL came back on as she pulled into the garage. I thought no way, not after driving 200 miles to the beach and back?? Pulled the engine cover off and what do you know...another cracked hose! And I think this was the one actually causing all the problems. Since I found the first one on the driver side I didn't think to check the passenger side.

Since I bought extra I cut a new piece, cleared the CEL, and tomorrow (or Wednesday) we'll see if it's finally fixed!!

 

Yes I found a couple on drivers side of mine but the biggest one is the ventilation hose #2 they call it (I found that after lots of searching) and I ordered and it will be in today and put back on. make sure to check that one as well, its a larger hose and insulated. Also Lexus part # after lots of searching is 1226250060, hope that helps somebody!

 

Thanks! Just ordered the two OEM hoses to replace the ones that were cracked (car is driving fine with the temporary hose in place, I'm just an OEM kind of guy lol).

Part numbers were 1734550050, 1734650050. Here is a diagram in case anyone else has an issue. You'll have to remove the engine cover to get to the clamps at the top of the hoses (btw the top was where the cracking occurred).