Evap expert help please! - Toyota Tundra Forums : Tundra Solutions Forum

stir_fry_boy · #1 (**permalink**) 04-28-2009, 12:30 AM

Have an 02 4Runner 4WD Sport 3.4 L. Been getting P0440, P0446, P0442 for a few weeks now, keep resetting each time I change something that I know is broken or failing. Changed my fuel cap with Toyota OEM, code still came on, found the VSV for VPS and that was stuck closed, so I changed that. When I pulled the canister it was dry as a bone. No overfills that I can tell, and the fuel check valve should be working becuase there was no gas in the canister. I didn't have any pressure in the tank before changing the VSV for VPS next to the canister, but now I do every time I fill up. Don't understand how I can have pressure in the tank and get the "big leak" code??
After resetting the codes, I am now just getting a P0440 code only. I really don't want to change the canister if I don't have to.
Truck runs good, gets about 21 MPG.
Question: Anything else I should check before I break the bank and buy the stinking canister???
P.S. I have the FSM.

mustang67408 · #2 (**permalink**) 04-28-2009, 09:54 AM

Before you buy the canister, I recommend the ORVR (fuel check valve). Even tho the canister is dry, the diaphram at the top of the ORVR may be leaking air thru a crack in the ORVR housing. All ORVR's are know for cracking (corolla/carmy/echo/mr2/sienna/ect..) and they give a P0440. The canister will not usually give this code and should be changed as a last resort. The ORVR is cheaper but requires you to remove the fuel tank to replace.
Pm me for a price if your interested.
If you carefully pressurize the tank and then squirt soapy water on the ORVR, you will probably find small bubbles coming out of the top of it along the rim, this is very typical and will always set a P0440.
just my opinion

stir_fry_boy · #3 (**permalink**) 04-28-2009, 10:30 AM

Do I squirt soapy water onto the ORVR through the vapor pressure sensor access? How do you pressurize the tank without the EVAP service tool?

mustang67408 · #4 (**permalink**) 04-28-2009, 10:34 AM

either thru the access or lower the tank just enough to see it.
you might be able to use a electric tire pressure pump thru the gas filler neck and seal it with a rag, you only need 3-5 psi of pressure.

stir_fry_boy · #5 (**permalink**) 04-28-2009, 10:47 AM

Is it very hard to take the tank out of the vehicle if it is pretty empty?

mustang67408 · #6 (**permalink**) 04-28-2009, 11:03 AM

remove driveshaft, place floorjack under tank on a piece of wood not to damage tank, remove straps and lower carefully so you dont break hoses or damage the wiring. Just low enough to squirt the soapy water and see bubbles.

stir_fry_boy · #7 (**permalink**) 04-28-2009, 03:58 PM

Can you estimate how long it would take an intermediate person with a fair knowledge to replace the check valve?
4 Hrs?

mustang67408 · #8 (**permalink**) 04-28-2009, 05:32 PM

we get paid 2.5 hrs, so 4 hrs sounds reasonable.

stir_fry_boy · #9 (**permalink**) 04-28-2009, 08:03 PM

If I am going to do this project, should I replace the fuel pump gasket along with ORVR just in case?

mustang67408 · #10 (**permalink**) 04-28-2009, 08:29 PM

Quote:

Originally Posted by stir_fry_boy

If I am going to do this project, should I replace the fuel pump gasket along with ORVR just in case?

couldn't hurt to replace while your there. Soak the bolts holding it on, just to make sure they come loose and do not break or strip.

stir_fry_boy · #11 (**permalink**) 04-29-2009, 12:06 AM

Just sent you a PM Mustang, no rush, just when you get some time. Also include shipping to 84116.

stir_fry_boy · #12 (**permalink**) 05-12-2009, 01:41 PM

Hey Mustang - My MIL came on again last night - code P0442 only. Can this still be the ORVR or is it something else? Before the code I cleaned the metal mating surface to the fuel gas cap. and made sure that the hoses were not damaged by the canister. So it went from a P0440 to a P0442 just by doing that.
Thanks

mustang67408 · #13 (**permalink**) 05-12-2009, 07:33 PM

Yes, P0442 would also be a ORVR. The P0440 could have been the cap and/or the ORVR. Thats why we use a scan tool to monitor the pressure to see where we are loosing it, and use a smoke tester and a EVAPORATIVE PRESSURE tester.

stir_fry_boy · #14 (**permalink**) 05-12-2009, 09:24 PM

So, in light of all of this what should be my next approach? Once again, I have replaced the VSV for VPS (Toyota), changed fuel gas cap (Toyota), checked the charcoal canister per FSM (works), checked other 2 VSVs under the hood per FSM (works), checked for damaged hoses all underneath, and checked the VPS per the FSM (works). Thanks for all your help. Oh, and one more thing: I have filled up several times and the gas pump has either clicked off early (tank not full, like half full) or not been able to fill the tank when it is empty. It doesn't happen every time, but it has happened several times. So, should I be leaning toward the ORVR given this symptom?

mustang67408 · #15 (**permalink**) 05-12-2009, 10:15 PM

Either take it to a dealer with a scan tool for exact diagnosis or examine the ORVR yourself with a light and magnafying glass and look for a crack (I'll try to post a picture of one that is cracked that I have laying around)(we do several a week on various Toyotas) if your unable to pressurize the evap system and spray soapy water on it to see small bubbles just replace it since you've pretty much covered everything else.