Hey folks,

I’ve been wrestling with an issue on my 2004 Lexus LS430 for about six months now. Every couple of drives—which is more than it used to—my instrument cluster lights up like a christmas tree with a red triangle on the dash, along with the check engine, traction control, and VSC lights. When I pull the code, it’s always P0442 (small EVAP system leak).

So far, I’ve swapped out what I think are all the EVAP hoses, the little black box next to the EVAP purge valve, and the gas cap. Is there a way to test and see if the purge valve (circled in red) is working properly or should I just replace it?

I’ve also noticed a strong fuel smell coming from the driver’s side rear wheel well every now and then. Not to be mistaken from the gas door area.

I’m wondering if the problem might be with the hoses around the fuel tank. Anyone know the best way to get to those? Do I need to pull up the rear seats or go through the rear fender liner? Also, I’ve attached a pic with some hoses circled in red that I wasn’t sure are part of the EVAP system. Should I replace those too?

Thanks a ton for any tips or advice. Y'all are lifesavers on this forum!

 

I would definitely get it on a lift and check out the tank. It may be a dry rotten hose on top the tank

 

see those little cracks in the hose in the last picture? that could be causing a leak. you can do a smoke test where you blow smoke from a cigar into the system and look for where its coming out. Check out some youtube videos for more info

 

Yeah, I saw that. Just wasn't sure it was a EVAP hose or something else. That hose seams to go really far down so I might just cut the end off and put a T fitting on it and a new small piece of hose.

 

I have gotten that code PO440 forever since my 15 car ownership which I've been told is most likely charcoal cannister related. Since I'm not going there, I've learned to live with it. The CEL will come on every now and then and then go off. There is a slight gas smell coming from the rear of the car. Since my car now has 176,000 miles, there are other things that would need attention before the cannister. PS... I remember changing just about every hose, box, emission related item and did the smoke test, which did not help resolve the problem.

 

I was having the same code (P0442) for 6 months and was not able to solve it until I replaced every single vacuum hose I could find in the engine bay. Before solving the problem, I searched every post I could find on the topic and several ppl were not able to solve the problem until they replaced the charcoal canister. They also noted gasoline odors in the rear of their vehicle that accompanied their problem (P0442), which sounds similar to what you're experiencing.

From what I understand, the replacement of this canister requires you to drop the fuel tank. However, there were people that were able to cut below the rear seat in order to gain the access needed to replace the charcoal canister. IIRC, there is a plastic hose barb that fails and causes the vacuum leak. If you try searching "charcoal canister" in the LS430 forum, you should be able to find more info on the process.

 

First, thank you for all the replies!

So far, I've replaced all the hoses in the engine bay, including the purge valve and the small black box connected to it. Unfortunately, this hasn't resolved the issue, so I think as y'all have pointed out, it must be the charcoal canister.

My wife mentioned that she saw a very small amount of gasoline on the ground on the driver's side of the car after I moved it. This was a while ago, and I haven't personally seen this, so I'm not entirely sure it was gasoline. I've been checking since then and haven't noticed anything. I'm wondering if gas could be leaking from the filler neck, a hose, or something else. Would this rule out the charcoal canister as the issue, since I wouldn't expect gasoline to leak from it?

Much thanks friends

 

Did you have any luck figuring this out? I’m having the same issue and I highly doubt it’s the canister