Check Engine - P0440 error Evap Emissions Malfunction

[Diesel]

Hi all,
I have a 1999 Outback S/W 95K. I bought it used and the head gasket was changed by previous owner at 86K. Shortly after buying it two months ago the check engine light went off. The code was P0440 - Evap Emissions Malfunction. After searching the internet and talking to mechanics I see it is a difficult problem to diagnose and correct. Any ideas or suggestions before I seek professional help (possibly for myself and the car) would be greatly appreciated!

Thanks in advance.

Bob K

[sivart7208]

thats wat i have right now (had for nearly a year) 02 126k miles and im goign to replace the o2 sensors, then the cat if that doesnt work.

[porcupine73]

sivart7208 I think you mean you have P0420?

P0440 basically means your fuel tank or related hoses and piping have a leak somewhere. Do you smell gasoline outside the vehicle at all? Probably won't if it's a small leak. Are there any other codes than just P0440?

Here's a few things to check. Make sure fuel filler cap is in good shape. Have it tested at a shop or just buy a new quality one for testing.

Check fuel filler pipe. On some Suby's (especially here in NY with all the salt!) the fuel filler pipe corrodes. See if there is a plastic 'cover' over your filler pipe in the wheel well. If so, remove the plastic cover and see if there's any serious corrosion of the filler pipe.

Those are the easiest things to check first. Other than that, there's a drain valve on the pack that could be having an issue. Purge control solenoid could be having issues. evap lines could be cracked. canister could be cracked or leaking. fuel tank could have a leak.

If the shop has a smoke machine that can detect small evap leaks that might be worth a shot. I've heard the smoke machines are very effective at finding leaks.

[freddiandgo]

We are also having a problem with P0440 code. First, we changed the gascap...no go. Then the filler thingy was changed (costing over $500). After 72 miles, the light and code were back. At that point we were due for inspection. The computer was reset...I drove about 75 miles with no light appearing, had it inspected...it passed. At 282 miles, (I should never have thought about that darn light!) it came back on.

This is really frustrating....how could we even sell it, if we wanted to? It runs well otherwise...no noises, no odor of gas....just the smell of me fuming!

We also have a Forester but now I'm wondering if we'll ever buy another Subaru, even though we need it here in the Catskills.

Not happy Outback owner.

Freddi

[porcupine73]

Hi and

Check out this article: http://endwrench.com/images/pdfs/EvapSpring04.pdf It has a good troubleshooting procedure. Replacing any part without first troubleshooting means the part replaced might not have been faulty. You just need to find a shop that knows how to troubleshoot and not just replace parts hoping it fixes the problem (can be hard to find a good shop these days). Someplace that has a good smoke machine for emissions leaks should be able to find the leak easily.

[ETC]

well first off let me say i understand the frustration troubleshooting evap codes, i'm doing it on my truck right now and these types of codes are without a doubt the most annoying thing i've dealt with on a car and i've dealt with a lot.

second i would say, don't blame the car. it's just doing what it's supposed to, telling you there is a problem. if you want to blame someone, blame the engineers who decided to have the vehicle throw specific codes even though the parts the codes reference have nothing to do with the problem.

here's an example;

my codes p0102 maf low voltage - did all the required tests for the wiring and pcm all check out- solution- replace maf ........ replaced maf - same code

p0443 purge solenoid low voltage did tests- replaced solenoid- same code

p0449 vent valve- low voltage - this is getting ridiculous ......... but wait..... my relocation bracket for my egr valve that's hidden under the blower is loose .... waiting on gaskets to see if that's my issue ................

basically to troubleshoot these issues you have to have complete understanding of how the parts all interact and the effect one can have on another. i know a few dealer mechanics and they actually do a lot of times just throw parts at these things because many times it's easier to just eliminate them as a problem, they also have access to these parts and don't have to pay if it doesn't work.

i'll let you know if the gaskets cure my problem, if so that may give you an idea of what to look for beyond the evap system.

sorry about the book, fortunately i can do my own testing and repairs so i save a few bucks, many can't and it's frustrating. you rely on a shop to not screw you and then ......... you get screwed. try to find a stand up shop that will guarantee their work, if you come back with the same code two days later they should admit they didn't fix the issue and credit you the cost toward the actual solution.

[vanamburg]

i know this thread is old im having the same troubles i was told by a mechanic i trust it was my fuel tank seam so i bought a new tank after a while it came back on and now it leaves me wondering what it could be i was told purge valve or canister. all lines seem to be good my filler neck is in great shape i dont smell gas/fumes anymore. idk where to turn and i dont wanna take it to a shop and advice would be great thanx in advance

[Michael M]

Originally Posted by freddiandgo

We are also having a problem with P0440 code. First, we changed the gascap...no go. Then the filler thingy was changed (costing over $500). After 72 miles, the light and code were back. At that point we were due for inspection. The computer was reset...I drove about 75 miles with no light appearing, had it inspected...it passed. At 282 miles, (I should never have thought about that darn light!) it came back on.

This is really frustrating....how could we even sell it, if we wanted to? It runs well otherwise...no noises, no odor of gas....just the smell of me fuming!

We also have a Forester but now I'm wondering if we'll ever buy another Subaru, even though we need it here in the Catskills.

Not happy Outback owner.

Freddi

I am sympathetic. In my case the light does not come on. My 2001 Outback JUST WILL NOT PASS CALIFORNIA CODE INSPECTION even though it passed smog. I need three Passing grades vis-a-vis codes. I am blessed to have a technician (independent) who meticulously went over every code and component. After two days narrowed down the problem to EVAP Code 0440. He will keep the Outback this weekend and do the drive cycle.

[illumin8ted]

I just got this code yesterday on a 1999 Outback Legacy. The car runs great. We recently moved to Colorado and had to pass an emissions test just two months ago. I'm curious what could have happened recently to cause this.

After reading these posts the obvious question comes up. What is the risk of not finding this issue?

This happens to be our primary family vehicle for now and want to be sure there isn't danger in driving it while we try to find the issue.

Any additional advice would be appreciated.

[Xnander Bishop]

I have a 1999 Subaru Outback as well and I have 2 codes, Catalyst converter under efficiency and EVAP malfunction. Is it possible that the 2 are related or 2 different issues. I would like to try and get these fixed so that I can move to Texas.