# EVAP leak question



## Jdoggsc (Dec 25, 2007)

Hey everyone

I've been getting the P0440 error code (i think it reads "EVAP system control malfunction." I looked through the FSM and followed the instructions to find where the problem was. I checked the voltage in the harness of the EVAP canister purge volume control valve (the first thing it said to check) and it checked out fine. I turned the car on and didn't see it moving at all though. I'm thinking it could be that I need to replace that valve. 

Just out of curiosity i looked at the "EVAP canister purge control valve" and it was covered in layers of greasy/gassy dust--you know what i'm talking about. NOthing else around it was covered except the valve and the 3 hoses that go to it (does anyone know which valve i'm talking about?







)

the main point:* is anyone else's purge control valve covered is grime too?* it is indicative of a leak in my opinion, so i'm thinking that's where the leak is. Autozone doesn't carry the parts, so i'm going to have to go to a nissan dealsership to get the parts and I'd rather not replace both if i can replace just that one.


----------



## IanH (Feb 11, 2003)

p0400 and p0440 check the hose under the EGR-BPTV, it rots out, $7 approx at the dealer


----------



## jdg (Aug 27, 2009)

I had the same code in my '98 200SX last year. Problem turned out to be dirty/cruddy connection back at what basically amounts to an old school charcoal canister.
It's behind the back left tire, under the car, kinda between the truck floor and the back/left fender. Look for some hoses, some wiring, and a box with a connector on it. Try pulling that connector off, clean it out, and put it back on. Gets really dirty and crappy back there. At any rate, it fixed my problem. And, I checked the same thing on my '97 Sentra. Same cruddy/dirty connection, although it hadn't caused a P0440 yet, I'm sure it would have eventually if I hadn't cleaned it.
Even if it's not the cause of your problem, checking/cleaning it is practically free and shouldn't take much more than 15-20 minutes of your time....


----------



## PhxJosh (Jun 27, 2009)

I have the same code, and mine is covered in grime too, I thought it was the canister at the back or a hoss, but I am with the OP and it may be the Evap valve?


----------



## Jdoggsc (Dec 25, 2007)

huh. i wondered what that box back there was for. The Haynes manual says it's in the back of the engine compartment but it's not. I'll check that tomorrow when it's light again--clean it out and stuff.

IanH, what is the EGR-BPTV? i got no idea what that is, so i don't know where to check the hose.


----------



## jdg (Aug 27, 2009)

Jdoggsc said:


> huh. i wondered what that box back there was for. The Haynes manual says it's in the back of the engine compartment but it's not.


My manual says the same thing, but the diagram under the hood shows different. I only found mine because I followed the vacuum lines.



> IanH, what is the EGR-BPTV? i got no idea what that is, so i don't know where to check the hose.


I'm not IanH, but...
Exhaust Gas Recirculation - Back Pressure Transducer Valve (I think)...
Basically, if you've got a lot of back pressure, the EGR valve doesn't have to open up as much to get the correct exhaust flow.
If you don't have a lot of back pressure, the EGR valve has to open up more to get the right flow.
Just check all of the hoses leading to and from the EGR valve and associated components. Why check only one if you're going to be in the area anyways?


----------



## IanH (Feb 11, 2003)

yes its next to the EGR valve.








the hose that rotted out was right where the text "EGRC-BPT valve" is
It was my Sentra that had that problem, with the GA 1.6
I dont know if the SR20 has one ?


----------



## jdg (Aug 27, 2009)

IanH said:


> the hose that rotted out was right where the text "EGRC-BPT valve" is


Come to think of it, I replaced that exact hose 2 years ago on my '98 200SX SE, not because it failed though. I just happened to be in the area messing with the fuel filter and noticed the hose was hard like a piece of brittle plastic and had 'ready to break' written all over it. Went ahead and changed all the vacuum lines and fuel lines under the hood. At least I feel safer for spending $20 and a couple of hours to replace 10 year old hoses/clamps.

Incidentally...aren't we getting our systems a bit crossed-up here? The code was P0440 for EVAP failure and we're talking about the EGRC-BPTV instead of the Evap purge valve. They might be all tied together and surely not a bad idea to check it anyways...
Just thinking we might be getting a bit off track...that's all...


----------



## IanH (Feb 11, 2003)

I had both codes and this rubber hose was all that was wrong, why I dont know.
Thats why i listed both codes together, this is a fairly common failure.


----------



## bbeauchaine87408 (Jul 6, 2009)

*Interesting...*

I had the EGR code which was fixed with the EGR-BPT hose replacement. I also had a P0440 as well which has not gone away - been too busy to track it down so far, especially since the service manual information on P0440 is nonexistent.


----------



## Jdoggsc (Dec 25, 2007)

so i checked the charcoal box just inside the rear bumper. The hoses look good there. There wasn't anything plugging them up or anything to clean out. I just put it all back together. I called up the local stealership. they want $250 for the EVAP purge volume control valve, and $130 for the EVAP purge control valve....seriously?!? I'm going to try to get some in a local junkyard. As far as the tube below the EGR-BPTV, i just checked in the FSM where that even is. i'll probably go do that tomorrow. hopefully it'll only be $7 at the stealership.


----------



## IanH (Feb 11, 2003)

well its $7.64 now on the courtesy web site....your stealership price may vary !!



cut and paste below couldn't get link to work directly ...remove quotes

"http://www.courtesyparts.com/kb_search_result.php?keywords=[14755P]+\%28b14u&cPath=3006_3007_3008_3020"


----------



## jdg (Aug 27, 2009)

There should be a check valve on top of the box itself. Maybe take that off and beat it up a little bit if there might be a little bit of crap inside of it. Are you sure there wasn't any electrical connectors back there? Mine are buried up on top of the box itself, up against the 'frame/trunk floor'. Kinda tough to see, but that's where they were and that's where my problem was. I can't imagine your setup being all that much different from the one I've got. Could happen though...
Incidentally, have you tried a new/different gas cap yet?
And maybe put a meter across all of those solenoids, check for continuity across all of the solenoid coils...


----------



## Jdoggsc (Dec 25, 2007)

jdgrotte, I tried unbolting the charcoal canister last night. I hosed everything down with PBBlaster and got the 3 bolts off fine, but something is screwed onto the side (the engine bay side) that I couldn't get the bolts off of. I got one off, but the other one is just spinning and I can't get it off without actually tearing it out of the plastic. Heck, for all i know, the bolt can't be tightened now and I've created another leak. I might have to replace that canister now? I didn't actually test the electrical connections. I guess i misread your post, so I thought you were talking about the hoses coming out of it.


IanH: wow, how have i never heard of that that courtesyparts website?!? that is amazing.


----------



## Jdoggsc (Dec 25, 2007)

maybe it has something to do with the weather/air temp, but this error hasn't re-surfaced for over a month now. heck if i know what changed...just glad it's not coming back anymore.


----------

