Finally solved my 01 4Runner p0440, had rear wheel fuel smell too. After replacing canister $295, gas cap $149 for diagnostics and cap, filler neck $189, vacuum switching valve and closed canister valve under hood $251 labor and parts, the code still kept coming back. Finally found bad vent valve on top of tank $535 labor/diagnostics and parts and its gone!!!!

 

very expensive fix!!

 

Yes, VERY expensive fix, hope my post can help others avoid those costs. I was going to a local shop at first, but finally went to the dealership for the final correct diagnosis, should have started there. It was an intermittent problem which was tough to diagnose though so I don't blame the local shop who has done great work for me in the past, often without charging me. If anyone has the P0440 code with the fuel smell at the rear, check the vent valve on top of the tank first before buying a canister.

 

Thanks for all the helpful feedback on fixing the underlying problems behind P044X codes. I'm getting an intermittent P0440 code on my 2001 4Runner every 150-200 miles, and want to focus on the right areas before throwing money at the problem.

My question for @scott b is: where ought I be smelling for the infamous "fuel smell in the rear"? Is it inside the 4Runner, or outside? Do I need to have the engine running or should I notice it at all times?

Are there any other areas I can check in a visual inspection to help narrow down what things I should replace and in what order?

 

On my 4runner I noticed it outside by the drivers side rear wheel , usually after driving on the highway. I would notice it when I shut it off and got out of the vehicle. I cant say which order to go in, possibly gas cap first, only use a Toyota gas cap, lots of problems have been reported with aftermarket gas caps, but I would suggest going to the Toyota dealer and have a smoke test done, usually costs about $120. I wish I would have done that first. Good luck

 

scott b,

Thanks for the quick response. I've ordered a genuine Toyota gas cap and will try replacing that first. If the code comes back, I'll start with a smoke test and see where things go from there.

I haven't been noticing a gas smell after driving, but I haven't been looking for one either. I'll be extra vigilant in the future to see if something doesn't smell right.

Cheers!

 

http://www.obd-codes.com/p0440
I thought the video in the above link was quite interesting. Smoke sure was helpful in diagnosing this one.


https://www.youtube.com/watch?v=aUOnrLz9u_M#t=255
This video was an eye opener How's the condition of your filler neck? Rusted and bent/deformed? Is it a known good quality gas cap?

 

Same deal here. Lights are on and I have been avoiding it since the canister is $350.

 

Ordered my gas cap today and a used canister. We will see what works first/. If this doesn't work then will try the smoke test. My dealer usually has a 10% off internet coupon for service.

 

aowRS, thanks for the excellent pics. Very helpful. Can anyone report back that the canister replacement fixed their problem?

I've been having fuel trouble for some time now. My problem is that I can't put gas in the tank without the fuel backing-up and shutting off the pump. It takes me forever to get $30 of fuel in the tank, but sometimes I'm lucky and the pump only stops for a few times. I took it to the dealership for routine maintenance and asked the service person about it. Answer, my 4Runner needs a new charcoal canister. Seems that these canisters get clogged up, valves plugged , etc. Price quoted for replacement/repair is $500. WOW! This is my third 4Runner, and never had this problem with the previous models (Gen 1 & 2). I'm wondering if this might be something different than a expensive canister replacement.

 

Did that fix the problem?

 

Lights were on for 3 months and suddenly went out a week or so ago. I'll take it

 

Andreas

 

Code came back so I bought the charcoal canister. 15 days ago and no lights so I think I am safe. $293 on Amazon was a steal I thought compared to $347 at Toyotapartszone and $475 at the stealer.