Androman

Hello again. I've been searching my dreaded p440 code for the last few months. Checked all the airbox hoses, looked at the charcoal canister, replaced a few parts, I think i have narrowed it down. I cant see it, but i can hear the vacuum leak. Its right above the gas tank, on the driver side, right in front of the back wheel. Im 99% sure its the overfill check valve. the Leak is very obvious, I just cant actually see it. Now, does anyone know if I have to drop the tank to get to it? or can I take out the back seat?

Please anyones help is much appreciated, I've been searching all over the internet and cant find anything on the RX overfill check valve. I know theres videos on other toyota's, but nothing for a 2001 RX300. or any RX300.

Thanks for any help

salimshah

Vacuum plumbing in the back is mostly accessible from below. The charcoal canister is enclosed in plastic shield. Try accessing from below and avoid the thought of dropping the gas tank. Then try from the cabin side [I have not tried that, so can say for sure what has to be removed. Hopefully a search on www will get you the answer.

Usually it is a hose that has come off so you can try wiggling them. In a pinch you can tape the crack over (blindly).

Salim

Androman

Thanks for the reply Salim. Unfortunately Ive looked over all those hoses. The only place i hear a vacuum leak is above the gas tank. Either a hose or the overfill valve. I just cant find anything about it.

dsil

Hi there. I'm getting code P0440 too. Searching high and low for the leak in the engine compartment, still need to inspect the rear of the vehicle. Did you ever locate yours?

salimshah

I hope you get the answer you are looking for, but seriously what are the odds of finding the leak at the same spot?

Not talking about the error code, but a leak is best found by isolating sections of the plumbing and running a smoke test or vacuum leak test. Smoke test has the advantage as it will take you to the right spot, while the vacuum test will keep narrowing the region down.

Salim

maxSteel

This thread should help you: https://www.clublexus.com/forums/rx-...o-i-check.html