hatchhero

yo tep keep me updated man. i also replaced solenoid and two way and still throwin p1457

TepEvan

Replacing the canister vent shut valve corrected the issue. I did have to replace the canister itself too.

MR.T

i've had this code for over a year now and for the last 6 months i've just had the system bypassed to open air. my car was running poorly and at the suggestion of a mechanic friend, i did an evap bypass, completely removing the connection to the motor and it instantly fixed my problem, but now it's time for an inspection and i need to get the system squared away.

i did the diagnosis per billman's instructions. everything seemed to be within spec as far as solenoid operations and holding vacuum. i tested the purge, two way and canister shut valves. i did notice that when i removed my canister that there was some gas in it and i also had some gas coming out of the two way valve when removed. i never have overfilled this tank. 99% of the time i'll only put 1/2 to 3/4's of a tank in it to help with weight reduction. my only guess as to how the gas got in the canister would be from evaporation from the tank settling in the canister low spot, since the bypassing of the system removed all vacuum purge flow.

any suggestions as to where to go from here?

MR.T

when i took out my purge solenoid for testing, it would make the clicking noise and hold positive pressure at both ends, but when i would apply vacuum to the canister side of the valve it would let air pass through and not hold a vacuum. does this sound faulty to you guys??




one more question... billman mentioned blowing a circuit breaker in his power probe when applying power to the bypass solenoid during testing. what type of gadget was this??? my bypass solenoid is clicking but i'm not sure how to properly test for a short in the solenoid.

MR.T

i know, i suck at simplifying things. so i'm going to reiterate my questions and bump this at the same time.

my two way valve and my bypass solenoid both passed bill's diagnostics. so i'm essentially stuck as where to look further

1. i need to know the best way to check if a solenoid is shorted out.

2. i tested the purge valve near the intake by removing it from the motor and applying power from the battery. there was a definite audible click. while in the closed position the valve would hold air all day long when i would blow into either port. BUT when i applied mouth driven vacuum to the canister side port it would not hold. sadly i went through this exact same scenario with my girls Toyota just last week. when i found out that her denso purge valve would not hold vacuum on that side either, i replaced it and the evap codes came back in 2 days.
so i'm thinking that this is not my problem, just the way denso designed their solenoid valves.

3. i took all of the evap parts out for a visual inspection and there was gas in my canister and two way valve. if i have gas in my canister should i just go ahead and replace it? not sure why there was gas in my canister, i'm 100% certain that it has never been overfilled. it may have something to do with me bypassing the system...reader further for those details.

back story to my evap problems a week after i got the car it started running with, what seemed like about 20-30% less power. i was new to the car, but this would be noticeable to anyone. a few days after the car started running poorly i threw a code, but when i checked it, it was P1457, an evap code.???? which in most cases have no affect on engine performance.

i went through the whole gambit of diagnostic procedures, leak down/compression test, new plugs, valve adjustment, dyno(to make sure i wasn't crazy) and was turning up empty handed, never imagining that my engine's performance was related to that evap code. the only noticeable thing besides the power loss was, when you were sitting still and revved the car, the motor would stumble and shake as you let off the gas and the rpms returned to idle. during the stumble/shake the rpms would drop close to 500 then level back out at a grand. honestly felt like a vac leak to me, but i couldn't find one anywhere in the engine bay.

at the suggestion of my mechanic i by-passed my evap system, completely removing the connections at the motor and tying the two vac ports off the intake together. the evap system was then being vented into open air with tubes i extended out of the hood/windshield wiper area and had no pull on it from engine vacuum.
immediately after doing so my car was back to it's old self and has been running great since.

so my theory is: whatever is bad in my evap system was a large vac leak to open air. just not sure what part of the system could fail and do this. once i get everything put back together, i guess i'll have to crawl under there while the motor's running and have a listen. any suggestions would be awesome.

MR.T

So my buddy says that once a canister gets liquid of any kind in it, which mine does, it is toast. So I'll be replacing that first along with a new canister shut valve.

Does anyone know the basics of how our cars perform their evap tests, how the vacuum is made, etc.... And how does the computer know the difference between a leak in the gas tank area(code P1456) and a leak on the canister side(code P1457) of things?

award78

any info on how to make this tester? or do I kinda need a spare engine harness laying around to use the cam sensor connector?
maybe just taking the whole assembly out would be easier. It looks like a bitch to get to the bypass solenoid......I cant even see it.

MR.T

you don't "really" need to make that. most of us don't have a spare harness laying around anyways.

just use these.

they're called gator clips. they'll fit right in there and will keep you from grounding out the battery by touching the wires together since they're insulated.

i got mine from radio shack and just used a 9v battery to activate each solenoid. although i did get a little better response from the solenoids by taking them over by the battery and using it's power, a 9v will work just fine for immediate diagnosis.

i highly suggest pulling down the whole assembly and doing the suck/blow test on all three solenoids and the rubber hoses of the evap system that bill describes in this write-up. you may have a solenoid that has an audible click, but may have some trash jammed in there from a deteriorating canister, or simply just a split or crack in a hose you can replace for .83$ a heads up though, the "evap purge valve" located in the engine bay will let some air through it if you suck on the canister side of the solenoid in a closed position. i don't care how new it is, it will still let air by. my girl has an 05 rav4 and while chasing down her codes her "denso" brand purge valve leaked by during the suck test. i though i'd found the problem, so i ordered a new one and right out of the box it did the same thing. and so does the "denso" brand purge valve on the hondas.

in my experience, all 3 of my solenoids checked out ok, but when i took the canister down for inspection some gas poured out. so knowing that the canister was ruined anyways, i went ahead and replaced that and it seems to have fixed the problem. i've been riding around for about a month now with no codes and satisfied monitors. this experience also seems to echo the same experience most others have had, and believe me, i did the research and messaged every s2k owner with this code. basically if it wasn't one of the 3 valves billman says to check, it was a bad canister.

if you do buy a new canister, go ahead and purchase a new "canister closed valve" my dealer told me that it came with one attached. it didn't... i only received an o-ring to replace, so i ended up having to take the "ccv" off anyways to install a new o-ring and would have rather replaced it.


good luck chasing down those black magic, ghost codes. they freaking suck

award78

you don't "really" need to make that. most of us don't have a spare harness laying around anyways.

just use these.
they're called gator clips. they'll fit right in there and will keep you from grounding out the battery by touching the wires together since they're insulated.

i got mine from radio shack and just used a 9v battery to activate each solenoid. although i did get a little better response from the solenoids by taking them over by the battery and using it's power, a 9v will work just fine for immediate diagnosis.

i highly suggest pulling down the whole assembly and doing the suck/blow test on all three solenoids and the rubber hoses of the evap system that bill describes in this write-up. you may have a solenoid that has an audible click, but may have some trash jammed in there from a deteriorating canister, or simply just a split or crack in a hose you can replace for .83$ a heads up though, the "evap purge valve" located in the engine bay will let some air through it if you suck on the canister side of the solenoid in a closed position. i don't care how new it is, it will still let air by. my girl has an 05 rav4 and while chasing down her codes her "denso" brand purge valve leaked by during the suck test. i though i'd found the problem, so i ordered a new one and right out of the box it did the same thing. and so does the "denso" brand purge valve on the hondas.

in my experience, all 3 of my solenoids checked out ok, but when i took the canister down for inspection some gas poured out. so knowing that the canister was ruined anyways, i went ahead and replaced that and it seems to have fixed the problem. i've been riding around for about a month now with no codes and satisfied monitors. this experience also seems to echo the same experience most others have had, and believe me, i did the research and messaged every s2k owner with this code. basically if it wasn't one of the 3 valves billman says to check, it was a bad canister.

if you do buy a new canister, go ahead and purchase a new "canister closed valve" my dealer told me that it came with one attached. it didn't... i only received an o-ring to replace, so i ended up having to take the "ccv" off anyways to install a new o-ring and would have rather replaced it.


good luck chasing down those black magic, ghost codes. they freaking suck
[/quote]
Thanks for the reply. This is going to be more painful than expected. 2 way valve and evap bypass sol. pass the test so I guess I'll move onto the canister. Which hose should I apply vacuum to test the canister or is it the shut valve I'm testing for vacuum?

MR.T

You'll have to remove the "canister shut valve" from the canister in order to test it. My screws holding on the shut valve would not come out, so I had to grind off the tops in order to remove the solenoid.

The canister itself is hard to actually test unless you have 5 arms or three friends to hold their hands over the ports while you suck and blow, haha.

Like I said, mine had gas in it, so it needed replacing anyways, but all of my research points to replacing the canister if everything else checks out ok.

Good luck man.