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P0440 EVAP problem

Discussion in 'Wrangler JK (2007-2017)' started by Jgolden93, Sep 25, 2016.

  1. Sep 25, 2016 at 9:38 AM

    Jgolden93 [OP] New Member

    Sep 25, 2016
    First Name:
    2008 jeep wrangler sahara
    So here's the problem I was first getting the p0456 and p0457 along with the gascap message. Took it to dealership got new filler neck and new gas cap....still on. Took back and said no leaks after a smoke test. So then I decided to replace the ESIM or leak detection pump on the evap canister. Reset lights went out for a couple days and got different code p0440 but no gascap light so I replaced the purge valve next to the battery. Reset it and back on again. The only thing left to replace in the system is the canister itself right? Or could I be missing something?
  2. Sep 25, 2016 at 7:44 PM

    C2T Well-Known Member

    Jul 31, 2016
    First Name:
    Helena, Montana
    2.5" AEV Dual Sport lift, 35" Treadwright Guard Dogs, Black Rock Wheels, AEV Front & Rear Bumpers with Tire Carrier, Fuel Caddy 10 gal. Aux. fuel tank, Warn 9.5ti, 125' synthetic winch line, front axle skid, 20" LED light bar , Bilstein Shocks, steel steering skidplate,
    I have not had to deal with this issue but here is the write up from a friend from a while back. you have already done some of this but I am going to post it in its entirety just the same:

    "There is the Evaporative System Integrity Detector which is the white Polymer module that is mounted to theEvap Canister. It's in essence an air flow sensor with a couple of check valves in it. Then there is the Evap Purgesolenoid which is located in the Engine compartment to the front right of theBattery and that's pretty much it on the electrical/electronic side ff the fuel evap system.

    if you want to self diagnose a bit here the following:
    Check the evap canister for any obvious damage/cracks.
    Check hoses for any damage/kinks, that includes all hoses from the filler to/from the tank, to/from the EvapPurgesolenoid, to/from the evap canister and vent filter (inside driver rear fender well by the filler neck).
    Check electrical plugs on the integrity detector and evap purgesolenoid.
    Take the filler cap off, inside in the middle there is a check valve, try to suck air through it (enjoy the fumes), the check valve should open with a little bit of resistance, if you try to blow air through it it should close completely.
    Check the evap purgesolenoid by pulling it out of it's retainer, then disconnect the tubing connected to the bottom the the solenoid, have someone start the engine and short after starting there should be air drawn in at the bottom of the solenoid (don't get dirt sucked in).
    Hope that helps"

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