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How to replace EVAP canister and valves


QuismO
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this is a how to on clearing the P1447 DTC that a few of us with an R50 has dealt with...i just figured it'd be helpful for those who run into this problem in the future as dealers have quoted me from $800-$1200 for clearing it and fixing the EVAP system.

 

I figured that it is also helpful as it's not a code that you should drive with as it builds pressure in the fuel tank which can cause fuel to spray out of the fuel filter or even the gas cap if the tank is full enough, making it an extremely dangerous fire hazard.

 

first off, the P1447 DTC is triggered when the EVAP control system isn't operating properly or there is a leak between the intake manifold and the pressure sensor. the parts between the pressure sensor and intake manifold are:

 

1. EVAP canister purge control solenoid valve

2. EVAP canister purge control valve

3. EVAP canister purge volume control valve (Part # 14930-3M201) $144.31

 

If you've received this P1447 DTC, chances are that the brick of charcoal in the canister has fallen apart over time, and filled the lines with charcoal. this affects parts 2 & 3 from the above list, and of course the EVAP canister (Part # 14950-1s717 $144.22). but when you replace the canister, you have to replace the EVAP canister vent control valve (part # 14935-54u06 about $100), and don't forget the o-ring (part # 16618-40u00 about $1.60) that goes between the canister and the vent control valve.

 

If you attack this DTC early enough, all you have to replace is the canister and vent control valve with the o-ring, which will add up to under $300 MSRP...a lot better than paying upwards of $1000 for parts and labor. Don't be scared to do it, it's actually quite simple.

 

Tools needed for the job:

Air compressor with tapered nozzle

Socket wrench set (10mm and 12mm sockets)

pliers

flat tip screwdriver

safety goggles

 

parts:

canister.jpg

canister part # 14950-1s717 $144.22

EVAP canister vent control valve (part # 14935-54u06 about $100)

o-ring (part # 16618-40u00 about $1.60)

-----------------------------------------------------------------------------

Total: around $245 plus tax

 

Time: 1.5-5 Hours DOE

 

Note: do this in the driveway as charcoal will be everywhere.

 

first, make sure that this problem is the same as yours...remove the hoses from the purge volume control valve and remove the two fastening bolts that hold it to the frame

purgevolumevalve.jpg

you can shake it around to see if little bits of charcoal fall out, if so, then you're in business.

 

open the gas cap to release pressure from the tank and then close it. put your safety goggles on as debri/dust/charcoal falls everywhere during the following steps.

 

locate the canister (not really a can, it's a black plastic rectangular box) located behind the left driver-side rear wheel, tucked into the bumper. use the pliers to slide the hose clamps away from the canister and slide off the hozes...the screwdriver can come in handy to initially pry the hoses off of the canister. next, there are 3 bolts holding it in place, 2 in the rear, one in front, all easily accessible, remove them and carefully drop the box down as there is a wire harness that is connected to the vent control valve, press the release tab until you hear the click, then pull off...i sprayed the harness with water to wash away the dirt so that it's easier to press the tab on the harness.

 

 

this is what it looks like after you've removed the canister:

canisterremoved.jpg

 

next, you'll have to go under the hood. on the corner closest to the steering wheel, you will see the purge valve and purge volume control valve. disconnect the hoses from these using the pliers and screwdriver. be careful not to break the plastic purge valve. shake all of the charcoal out of this little plastic guy and then finish it off with a can of compressed air.

 

next, get the volume control valve (look at picture above) and unscrew the two screws that hold the halves together. clean the o-ring and wipe the cylindrical cavity clean. in the other half, you will see two more screws, unscrew the two and separate this half into fourths and a step motor will be revealed. be careful when pulling these two apart as there is a spring inside that might fall out. clean the magnet and lubricate it with wd-40 while turning the magnet and ball-bearing washer. ground charcoal makes it hard for the step motor to function smoothly. as you turn the magnet back and forth, you should see the grey plastic valve go up and down. wipe the parts dry and assemble. before putting the two main halves together, plug the purge volume control valve into its harness and turn the ignition to the "on" position, you should see the valve go up, and when you turn it off, it should go back down. if you've cleaned it all you can, and it still doesn't go up and down, then you might need to get a new purge volume control valve for about $150.

 

remove the air intake box by removing the 3 bolts/nuts. next to the intake box cavity, you will see the network of EVAP hoses and other sensors/valves/solenoids. unplug the two hoses that lead to the engine block (remember which hoses go where), and the one that comes from the plastic purge control valve. then remove the three bolts/nuts that hold the hose assembly to the engine bay wall:

airboxremoved.jpg

 

this is what you'll get:

IMG_1895.jpg

this makes it easier to unplug the hoses from the sensors/solenoids/valves as these are plugged onto plastic tubes that are little more delicate. a can of pressurized air should suffice to blow out these lines.

 

now you'll now have to lay under the pathy. scoot yourself under the rear axle, as if you're go to change the fuel filter, there is an L-shaped rubber hose connected to metal tubes of the main EVAP line, you can probably disconnect one end of the rubber hose, if you can't, no worries, i was tired from work and then this, so i skipped it =P but if you can, great, even more thorough.

 

here's where it is, highlighted in purple

underpurgeline.jpg

 

 

After all of the above is done, you're ready to blow out the main line. get your air compressor and blow in from the engine bay:

 

blow into the hose highlighted in red.

purge-1.jpg

 

if you've disconnected the L-shaped rubber hose near the fuel tank, then you should get some charcoal shooting out of that area, if you didn't, then the charcoal will shoot out of where the canister was in the driver side rear area. i didn't have much charcoal as most was still in the canister, but if you've driven long enough with this problem then maybe you might get a little more.

 

once you've blew them all out, connect all the valves and hoses in the engine bay. then you'll have to connect your new vent valve to your new canister, don't forget to put the o-ring on the canister. once the vent valve is on, bolt the canister into place, connect the wire harness to the new vent valve, and connect the 3 hoses accordingly.

 

Then clear the ECM DTC by following the steps located in the garage>how-to's THREAD. hopefully the MIL/SES light shouldn't come back on (assuming there is nothing else wrong with your pathy).

 

MANY THANKS GOES TO VENGEFUL AND XPLORX4 for saving me $1000 so that i can do this myself.

 

GOOD LUCK!

ian quismo

Edited by QuismO
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Great write-up Quismo!!! Thanks. This should be pinned up in the how-to section. I think I am going to have to do this job in the near future. I got the 1447 code like 2 months ago found out what I was looking at but the light went out like 3 days later and has not come back on since. I even ran the codes again at VATO-ZONE and had no codes so I am ok for now but the Evap cansiter is suspect.

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  • 3 years later...

I have a quick question, in researching the fact that I have granules in my EVAP lines and I need to replace the canister, I haven't found why I need to replace the EVAP canister vent control valve. Can someone tell me why this is also necessary to replace?

 

Thanks,

Kevin

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To avoid paying the $200 in parts for the canister and valve, I sourced a canister and valve from my local salvage yard for $15. I followed the instructions and installed the used EVAP canister and after a day of driving, no CEL code. My sourced junker was a 99 to be used on my 97 for reference.

 

Thanks for the great write-up.

-Kevin

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  • 1 month later...
  • 1 month later...

Just an update on this, after 2 months mine R50 is running fine.

 

If you go the wrecker route, make sure to tap the canister with a screwdriver handler and make sure nothing comes out.

 

Take the time to dismantle and clear the the Purge volume control valve,it will take about 20 minutes to do right, get all the carbon flecks out of there. Use a small flashlight to make sure.

 

I used a shop vac and a lot of duct tape to clear the lines, from the engine end and gas tank end.

 

If you take your time this should get you up and running with minimal problems.

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  • 1 month later...

I just noticed that Canister on my '01, is it a California Emissions thing or do all R50s have it? In other words, why can't I just remove it?

 

Thanks for the info BTW, I'm saving this if I ever need to change mine out.

Edited by RedRider3141
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  • 1 year later...

Excellent writeup!

 

Thanks for the help, I just took my Evap system apart. The lines were filled with charcoal. (Driven many miles with the check Evap warning)

The local Mech replaced the Evap canister and the vent valve and the purge valve up front without clearing the lines.

I checked the lines and a ton of charcoal came out. I shook out the front purge valve and the volume control valve and the hoses. I must have collected 1/4 cup of charcoal.

 

I disassembled the volume control valve, blew it clean and wiped it out with a paper towel soaked in WD40.

Then I disconnected the evap lines at the canister end and blew the lines out from both ends of the car using a compressor.

 

Not sure if I got it totally clear. Even after repeated high pressure attempts from both ends, there seems to be a fair bit of backpressure when stuffing the nozzle into the line. But my helper (okay my 13y/o kid) said airflow could be felt out of the line up front when I had the compressor nozzle blasting from the back end.

 

All cleaned and reassembled, reset the OBD-II at Autozone. Fingers crossed...I need to get this badboy inspected!

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  • 1 month later...

Hi guys Im new here, =) I have a 98 Infiniti qx4 which is same as a pathfinder. And I got an Engine light which throws the codes P0440 and P1448 and I know that this a for a small leak in the Evap system. My car also sometimes stalls after a start, and takes a couple tries to make it start with accelerating. It also did shut off on me on the highway while I was driving a couple times. Not common but it did happen before.

 

After that I cleaned my Evap lines. Blew compressed air through the lines by making sure there is no pieces of charcoal. The lines turned out to be clean. While the cleaning the lines I had the battery disconnected so the engine light was gone after I was done. So after that the car ran ok for a week and then the engine light came back AGAIN. The car started having rough starts again but never stalled on me while I was driving since I cleaned the lines (but maybe it's just a matter of time)

 

Any idea what this might be??? Bad Evap control valve, not opening properly or what???

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  • 4 months later...

Trying to fix my 98 pfinder, showing the evap codes listed in the how-to.

 

My purge volume control valve does not look like the one in the writeup; looking at where the line taps into the intake manifold and working backwards, this is what I have for a valve:

 

http://www.qualityresale.net/product/97-05-nissan-altima-maxima-350z-murano-purge-solenoid-vsv-switch-valve

 

I pulled the hose off the side leading away from the valve (not the manifold side) and started the engine.

Shouldn't I feel a vacuum when the car runs?

 

If I pull the manifold side off the valve, idle rpm drops immediately.

 

How can I test this to make sure it's toast?

 

Thanks

Ted

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  • 1 month later...

I just wanted to thank you for posting this and making it a how-to. I had the P1444 code, so I went and got a fuel filter and put it in-line. There was a lot of charcoal that came out of the purge valve and the line actually had a charcoal blockage, so I got that cleared, then I started my Pathy up and the SES light didn't come on!!

 

Eventually I'll have to replace the canister and blow the line out, but I needed a quick and dirty fix right now so I can pass my smog test before this week is over. The SES light coming on a few days ago couldn't have been at a worse time, but reading about the solution here was great. The best part is I didn't have to take it to the dealership and pay out the nose to have them fix it.

 

Thanks again!!!

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  • 7 months later...

quizmo...excellent description of this...i fixed mine in almost no time...some screws were a pain in the ass...though 1 question?

i did blow air into the hose...i could get to the hose near the fuel tank..so i replaced everything and put it back together...was gonna wait a week or so to take the engine hoses apart again to see if anything comes out!,,, will it be ok or should i take it apart and blow it out now??

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  • 8 months later...

I am a lady with almost no mechanical experience I've done some car work on engines but never changed a tire.

Anyway, I pray a blessing upon the kind soul who published this information.

I couldn't afford to pay a garage and was lucky I was able to afford the parts but these instructions were right on. I got my required tools and set to work.

If I had to give one extra piece of advice that I didn't think of ahead of time but probably for your average mechanic it's common sense.

Spray the bolts on the canister before trying to remove them. Like techron and spray them the night before to avoid breaking the bolts as they get pretty bad.

So if I can do this job just your average lady any one can. I had one advantage too. I was so small I didn't even have to jack it up.

But my truck is fixed, with my own hands at that I'm thrilled that I learned and was able to do something like this. With out these instructions I doubt I;d of had the confidence to even try...... THANK YOU SO MUCH.

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  • 7 months later...
  • 7 months later...

post-37797-0-82491700-1431224186_thumb.jpg

 

Am I dyslexic or is this part really backwards? What gives?

 

We got it plumbed up and all, but it was a pain to stretch the fresh air tubing.

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I would add that the code mentioned is an.OBD II non continuous monitor. Meaning that if the code is cleared that it may need to driven several times before the engine computer will run the code diagnostics again. However this is an great write up for an common problem for this model pathfinder.

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  • 2 years later...

Hopefully someone will help me on this. I got the code P1441 replaced vacuum cut bypass valve and vacuum cut valve. Fixed my problem. Now no cil, but I have a crazy amount of pressure coming out when I take the gas cap off. I have a 97 qx4. I know there is supposed to be some pressure that comes out but this pressure is so much that it lasts for a good five seconds. I know this is not normal. What could be causing this? I know it's not safe to drive like this. Could it be something from inside the tank? What line runs to the gas tank for ventilation to come out if there is one. I've taking hoses off the canister see no charcoal anywhere. I have even removed the canister and turned it upside down all around and nothing comes out of it I hear no charcoal rattling around inside of it either. PLEASE HELP

 

Sent from my Z836BL using Tapatalk

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