Interesting EVAP issue

So I decided to finally scan my engine check code that has been on for years, hoping to finally figure out why my MPG is so low (16-18hwy). I think the code was a P0441 which is something like " EVAP insufficient purge flow". So first thing I do is replace the purge solenoid. $13 bucks later im doing the "drive cycle" to see if I fixed the problem. 20 or so miles later I re-scan to see if all the sensors have passed and low and behold the same code again, this time no engine check light ( not yet ). Next step I take off the EVAP purge switch, for some reason I decide to blow through it to see if its clogged. I begin to blow into it and a bunch of tiny balls start flying out of the purge switch, I imagine this is charcoal from the canister. there is also a few balls in the newly installed purge solenoid. So have I been sucking charcoal balls into my engine this whole time? and could I safely say that somehow the canister went bad allowing charcoal to be sucked upstream into the engine?

Those little balls, are now everywhere. They've made the journey through vacuum hoses and EVAP lines all the way up to the Purge Valve. The Insufficient Flow code will continue to come back until you clear all the lines and solenoids out. It's possible that the Canister is full, but it's a rarity. Sometimes, carbon deposits (the little balls) just decide that they want to explore the EVAP system, and leave the Canister. Or, somehow someway, a line got switched from a suck to a blow causing a little carbon ball fiesta.

I cleaned out all the carbon from switch and solenoid. I got a 200 mile drive coming up on saturday so ill relog my mpg, ill also recheck the system for carbon deposits when I return. Thanks for the info!

Np. I'm curious if a vacuum or EVAP line going to the tank isn't plugged up. If the EVAP line going TO the tank gets plugged, it might just cause a vacuum or pressure situation inside the Canister, and the Purge could suck the balls (haha) up to the engine.
Like I said, it's a very rare occurrence. The last time I saw it happen was when my old boss hooked the vacuum lines up wrong on his Carburetor and sucked 'em into the fuel bowl. That was fun to clean out......

Obviously, if it happens again, there's an issue somewhere. If the Canister is full of fuel, you'd more then likely be able to smell it from under the car. If it does happen again, you can get up there and disconnect the EVAP lines from it and see if you get wet...

Well today I pulled the charcoal canister out. Some carbon balls do come out when I shake it upside down but not a whole lot. Also blew into the hoses leading to both the tank and the engine and both seem to be clear. reset the code and let the wife take it to the store. she came back and sure enough I get another P0441 code but without the check engine light. the error seems to alternate between P0441 and P1441. not to sure what to do at this point. Spend the $100 on a new canister? Air does flow through the canister and the error indicates " insufficient flow" so im not thinking this is the problem. nothing left to check on the EVAP system

Oh wow. So you're getting Flow during Non-Purge AND No Flow During Purge codes randomly.
If everything appears to be ok, I say replace the canister. A damaged canister will absolutely cause this issue.

The following is right out of my Service Information. I highlighted the canister part for you. Have a read...


•Poor connection at the PCM.
Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.

•Damaged harness.
Inspect the wiring harness for damage.

•If the harness appears to be OK, observe the EVAP vacuum switch display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display will indicate the location of the malfunction.
•Malfunctioning or damaged canister.
A malfunctioning canister may intermittenly allow charcoal into the EVAP purge solenoid, vacuum switch, and associated lines causing a DTC to be set. Use the following procedure to check for a carbon release condition:

 1. Turn OFF the ignition switch.
 2. Remove the EVAP purge solenoid. Refer to Evaporative Emission Canister Purge Solenoid.
 3. Remove the EVAP vacuum switch. Refer to Evaporative Emission Vacuum Switch.
 4. Lightly tap the purge solenoid and (if applicable) the vacuum switch on a clean work area looking for carbon particles exiting either of the vacuum ports.
 5. If no carbon release is evident, reinstall the components and continue with the DTC P0441 diagnostic table. If carbon is being released from either component, continue with this service procedure.
 6. Remove the charcoal canister from the vehicle.
 7. Ensure that the main cylinder valve is turned off on the J 41413 EVAP purge/pressure diagnostic station.
 8. Disconnect the black hose that connects the nitrogen cylinder to the EVAP purge/pressure diagnostic station at the pressure regulator by unscrewing the knurled nut on the regulator. No tools are required to remove the black hose from the regulator.
 9. Using a section of vacuum line, connect one end over the open threaded fitting of the EVAP purge/pressure diagnostic station pressure regulator.
10. Connect the remaining end to the purge solenoid end of the EVAP purge line at the vehicle and turn on the main nitrogen cylinder valve. Continue to blow any debris from the purge line for 15 seconds.
11. Return the EVAP Pressure/Purge Diagnostic Station to its original condition by re-installing the black hose that was disconnected in step 8.
12. Replace the following components:
◾The EVAP purge solenoid. Refer to Evaporative Emission Canister Purge Solenoid.
◾The EVAP canister. Refer to Evaporative Emission Canister Replacement.
◾The EVAP vacuum switch. Refer to Evaporative Emission Vacuum Switch.
13. Proceed with the DTC P0441 diagnostic table.
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

Next question, how many people here end up removing the EVAP system all together?? And will it really effect my mpg that much?

It won't really affect your MPG's I don't think. I'm not quite sure how you'd keep the fuel tank vented though. I suppose you could use the main EVAP line from the tank as the vent hose, and maybe hook it in the the Intake somehow. I'm not sure, I've never done it.

If you have somebody you know with a tuner, you can literally go in and turn the EVAP system off. There is a subsection in the DHP that allows you to change every single trouble code in the PCM. In this section, you can set any code to "reporting" or "non-reporting". I currently have all of my Catalytic Converter and rear O2 codes shut off on my car, and had to turn SirPsycho's EGR functions off (he has no EGR) on his new engine. So, it is possible to ignore EVAP switches and sensors without physically removing them.

IF, this is causing the low mpg I admit to not knowing-----If you are getting only 16-18 mpg instead of 24 mpg or so, you are paying for the new canister now but not getting it. At $4 per gallon you would pay for a $100 canister in 1200 miles.

Abaddon wrote:

It won't really affect your MPG's I don't think. I'm not quite sure how you'd keep the fuel tank vented though. I suppose you could use the main EVAP line from the tank as the vent hose, and maybe hook it in the the Intake somehow. I'm not sure, I've never done it.

If you have somebody you know with a tuner, you can literally go in and turn the EVAP system off. There is a subsection in the DHP that allows you to change every single trouble code in the PCM. In this section, you can set any code to "reporting" or "non-reporting". I currently have all of my Catalytic Converter and rear O2 codes shut off on my car, and had to turn SirPsycho's EGR functions off (he has no EGR) on his new engine. So, it is possible to ignore EVAP switches and sensors without physically removing them.

..as long as the emissions inspector does not do any forensics to determine if you are that mod.

I do not know what the CARB rules are for 17 yer old cars in California.

albertj wrote:

Abaddon wrote:

It won't really affect your MPG's I don't think. I'm not quite sure how you'd keep the fuel tank vented though. I suppose you could use the main EVAP line from the tank as the vent hose, and maybe hook it in the the Intake somehow. I'm not sure, I've never done it.

If you have somebody you know with a tuner, you can literally go in and turn the EVAP system off. There is a subsection in the DHP that allows you to change every single trouble code in the PCM. In this section, you can set any code to "reporting" or "non-reporting". I currently have all of my Catalytic Converter and rear O2 codes shut off on my car, and had to turn SirPsycho's EGR functions off (he has no EGR) on his new engine. So, it is possible to ignore EVAP switches and sensors without physically removing them.

..as long as the emissions inspector does not do any forensics to determine if you are that mod.

I do not know what the CARB rules are for 17 yer old cars in California.

Well as of right now I have the EVAP capped off on the throttle body, and the hose simply disconnected from the solenoid so the tank can still vent. I'm not worried about emissions because even though I live in Cali, I am military so I can maintain my Florida tag ( which does not have emissions of any kind )   As for my BMW, having all kinds of issues trying to get it smog'd because of a engine check light that changes code every time I fix something  

96_Juggernaut wrote:

...
As for my BMW, having all kinds of issues trying to get it smog'd because of a engine check light that changes code every time I fix something  

keep in mind that the code does not automatically point to the bad part. (O2 sensor, for example - many many different things can cause an O2 sensor code, and replacing the O2 sensor is not the answer unless the code was actually "bad O2 sensor"... usually it's 'out of range' or 'bank lean' but people see O2 sensor and just replace it... when the problem was a vacuum leak, or bad injector, or bad MAF, etc...

(I'm not a BMW guy, but if you are chasing codes like this you should step back and look for the real problem)