P0441 / 1441 EVAP Emission Canister Purge - keeps coming back!

Eldo wrote:

Thanks for the confirmation of my memory... But how can the system test itself without a solenoid to control the venting?

As you yourself just stated above, the bottom tube (on the Vacuum Switch) has a vent, which is what the Vent solenoid eventually replaced

Hey great, thanks for that info guys, thats what I thought but I just wanted confirmation, I hate having questions marks.

I think I finally solved my problem. I got this idea from a how-to on the B-body forum I am a member of. It was mentioned that when the charcoal canister starts to fail it will send pellets up the line. What happened in my case if they got all the way up to the purge solenoid and jammed it in the open position. I took the valve out and cleaned it out with a pick and compressed air. I tired apply 12v to it at times, but it still wouldn't operate. I gave it a few smacks with a hammer and a little more pellets came out and now it opens and closes as it should. I also cleaned some pellets out of another part in the system (round one right before the solenoid valve). I then stuck a small piece of steel wool in the elbow going to that round part (maybe a sensor?) to prevent the pellets from getting into the valve again, and it allows the fumes to flow.
So far I have put a couple hundred miles on the car with no CEL, much better than the 20 miles I got before it came on before.

moldymac wrote:

I think I finally solved my problem. I got this idea from a how-to on the B-body forum I am a member of. It was mentioned that when the charcoal canister starts to fail it will send pellets up the line. What happened in my case if they got all the way up to the purge solenoid and jammed it in the open position. I took the valve out and cleaned it out with a pick and compressed air. I tired apply 12v to it at times, but it still wouldn't operate. I gave it a few smacks with a hammer and a little more pellets came out and now it opens and closes as it should. I also cleaned some pellets out of another part in the system (round one right before the solenoid valve). I then stuck a small piece of steel wool in the elbow going to that round part (maybe a sensor?) to prevent the pellets from getting into the valve again, and it allows the fumes to flow.
So far I have put a couple hundred miles on the car with no CEL, much better than the 20 miles I got before it came on before.

and you replaced the charcoal canister, Right?!?!?


Albertj

albertj wrote:

moldymac wrote:

I think I finally solved my problem. I got this idea from a how-to on the B-body forum I am a member of. It was mentioned that when the charcoal canister starts to fail it will send pellets up the line. What happened in my case if they got all the way up to the purge solenoid and jammed it in the open position. I took the valve out and cleaned it out with a pick and compressed air. I tired apply 12v to it at times, but it still wouldn't operate. I gave it a few smacks with a hammer and a little more pellets came out and now it opens and closes as it should. I also cleaned some pellets out of another part in the system (round one right before the solenoid valve). I then stuck a small piece of steel wool in the elbow going to that round part (maybe a sensor?) to prevent the pellets from getting into the valve again, and it allows the fumes to flow.
So far I have put a couple hundred miles on the car with no CEL, much better than the 20 miles I got before it came on before.

and you replaced the charcoal canister, Right?!?!?


Albertj

That sounds like you may get the code again sometime down the road. The charcoal canister is giving up pieces of charcoal which means the method they use to keep the charcoal in the canister has been breached and you will continue to get movement of charcoal down the line and eventually clog up the steel wool you put in there.

Now that you know what the problem is and you've bought yourself a little time, you may want to try and get a replacement canister assembly, be it used or new, if cheap enough.
I don't know what new costs and if they are available through the aftermarket or not.
I know if it were mine I'd be replacing it with something before the bad weather sets in.

If the canister isn't already leaking fumes it will be soon. That is the worst kind of gasoline leak you can have. Fumes are more volatile than liquid, but if there is not enough charcoal to absorb the fumes and hold it in suspension then you are asking for possible trouble, never mind smelling gas fumes all the time. Especially after you shut off the car or upon start-up is when you may start to smell it first then gradually all the time.
The canister is not one of those item you can remove from the car and not worry about it being missing. That system needs to work properly for your safety and the way the car is meant to run with it working. Just because you got the light to clear doesn't mean there isn't trouble brewing under there.
Just my $0.02

Rickw wrote:

That sounds like you may get the code again sometime down the road. The charcoal canister is giving up pieces of charcoal which means the method they use to keep the charcoal in the canister has been breached and you will continue to get movement of charcoal down the line and eventually clog up the steel wool you put in there.

Now that you know what the problem is and you've bought yourself a little time, you may want to try and get a replacement canister assembly, be it used or new, if cheap enough.
I don't know what new costs and if they are available through the aftermarket or not.
I know if it were mine I'd be replacing it with something before the bad weather sets in.

Just my $0.02

This is a bandaid on at best right now. Now that I know what caused it, its time for a charcoal canister. Is it in the rear bumper on these cars?

I noticed rock auto sells a charcoal canister filter for a whole $1.48. Has anyone tried replacing this filter? A delco can is $69, so its not too expensive if I have to replace the whole thing.

moldymac wrote:

This is a bandaid on at best right now. Now that I know what caused it, its time for a charcoal canister. Is it in the rear bumper on these cars?

The location of the canister is under the car near the fuel tank.
It isn't hidden, it's in plain sight when you have the car up on jsack stands or a lift.

moldymac wrote:

I noticed rock auto sells a charcoal canister filter for a whole $1.48. Has anyone tried replacing this filter? A delco can is $69, so its not too expensive if I have to replace the whole thing.

The $1.48 filter is just a foam type filter, not the replacement charcoal itself.
I think you'll have to replace the canister to solve your issue with the charcoal escaping.
But you can try removing the unit (Take Pics) and see if you can COB it together so it doesn't spit more charcoal or buy another one. Depends on budget and ambition to crawl under once to replace it or multiple times to COB it.

Please take pic's of the unit on location and off on the bench. Also, if you can disassemble and attempt a repair on the bench, please document that as well.
We don't currently have any good pic's of the EVAP Canister being disassembled and reassembled. A good opportunity for most of us that have yet to encounter the problem your having.
Thanks a lot,
Rick

Congratulations on figuring out your problem, David. That was a weird one...

I agree, though, that you'd better find a new canister. Morad probably has one on a Rivi in the yard, else they can probably cross reference it to another model. Hell, I checked a few online sites and they come up for Pontiac, Olds, GMC and Buick - for around $70 brand new. They appear to be using stock pictures of round ones, however one close-up photo shows that it isn't the actual part number for the rectangular one.

My Parts List says that for a 95 to 97 they are the same P/N
GM = 17113065
Flat Rate Labor to R&R Vapor Canister is .4 or 24 minutes.

For 98 to 99 GM = 17113332

Bracket for 95 to 97 GM = 25609304
and for 98 to 99 GM = 25696423

Purge Valve for 95-97 GM = 1997210
98 = 1997278
99 = 1997289

Hope these numbers help in researching cost's and availability.

Rickw wrote:

My Parts List says that for a 95 to 97 they are the same P/N
GM = 17113065
Flat Rate Labor to R&R Vapor Canister is .4 or 24 minutes.

For 98 to 99 GM = 17113332

Bracket for 95 to 97 GM = 25609304
and for 98 to 99 GM = 25696423

Purge Valve for 95-97 GM = 1997210
98 = 1997278
99 = 1997289

Hope these numbers help in researching cost's and availability.

Thanks for the P/Ns. I am going to pull the old one and have a look at it first, but will probably end up just replacing it.

Haven't had any problems like this with the Riv, but my wife's '99 Toyota had a similar problem a few years ago. Reading up on it, the charcoal canister needed replaced. It's a design flaw with these cars, costs $400-700 to fix. The consensus in the Toyota community was that you can run with bad EVAP system (bad canister) and no ill effects, except emissions check. Our car has been fine for over 3 years now. No leaking gas or fumes that I can tell. No other codes, car runs great, hasn't blown up yet.

So, does our system work that much differently? What makes our EVAP system design so dangerous when it fails?

AA wrote:

Haven't had any problems like this with the Riv, but my wife's '99 Toyota had a similar problem a few years ago. Reading up on it, the charcoal canister needed replaced. It's a design flaw with these cars, costs $400-700 to fix. The consensus in the Toyota community was that you can run with bad EVAP system (bad canister) and no ill effects, except emissions check. Our car has been fine for over 3 years now. No leaking gas or fumes that I can tell. No other codes, car runs great, hasn't blown up yet.

So, does our system work that much differently? What makes our EVAP system design so dangerous when it fails?

Depends on the mode of failure. Similar does not equal identical, and even if it did this is not a $700 problem on the Riv, anyway.

Since the canister gets fumes purged as well as put in, a used one is not a terrible bet as it's not likely to be exhausted. However, that said, a new one does not cost a fortune and (due to the design specs) is likely to last another 150,000 miles +/- 50K.

So given the temporary fix in place, if it was mine I'd happily shop around for an inexpensive new canister and maybe a purge valve. I would purchase the new canister and depending on the $$ a new purge valve, install them, and be done with it.

What do you think?

Albertj

I noticed that the line that runs to the evap service port by the rear of the engine is kinked and is starting to crack. Can I buy a new line or will I need to repair it with some vacuum hose and fittings? Will there be any problems driving the car while it is cracked?

https://2img.net/r/ihimizer/img715/9765/dsc00076uq.jpg

You may throw an evap code, but those nylon lines are replacable with a kit sold at many auto parts stores. IIRC you need to warm one end of the new line to soften it to allow you to slip it over the steel line.

deekster_caddy wrote:

You may throw an evap code, but those nylon lines are replacable with a kit sold at many auto parts stores. IIRC you need to warm one end of the new line to soften it to allow you to slip it over the steel line.

So far I haven't thrown a code. Do you have a link or know where can I find the kit in the store? Will it be behind the counter or on the shelf?

98riv wrote:

deekster_caddy wrote:

You may throw an evap code, but those nylon lines are replacable with a kit sold at many auto parts stores. IIRC you need to warm one end of the new line to soften it to allow you to slip it over the steel line.

So far I haven't thrown a code. Do you have a link or know where can I find the kit in the store? Will it be behind the counter or on the shelf?

just google "Nylon Fuel Line Repair Kit" for a few results that are close. There are different sizes, etc. In some stores I have seen it on the shelf (hanging rack of HELP/Dorman parts). In some stores not. From my google search, some have straight ends, some have elbows, etc... try rockauto.com and see if they have a listing for our specific application.

deekster_caddy wrote:

98riv wrote:

deekster_caddy wrote:

You may throw an evap code, but those nylon lines are replacable with a kit sold at many auto parts stores. IIRC you need to warm one end of the new line to soften it to allow you to slip it over the steel line.

So far I haven't thrown a code. Do you have a link or know where can I find the kit in the store? Will it be behind the counter or on the shelf?

just google "Nylon Fuel Line Repair Kit" for a few results that are close. There are different sizes, etc. In some stores I have seen it on the shelf (hanging rack of HELP/Dorman parts). In some stores not. From my google search, some have straight ends, some have elbows, etc... try rockauto.com and see if they have a listing for our specific application.

Thanks for the help! That does look like the part I need.

I recently got a code P0441 on my '96.  So this means that the vacuum switch does not "switch" when the purge solenoid opens a pathway for engine vacuum to draw gas fumes from the vapor canister which has the charcoal in it.

Does anyone know if the Vacuum Switch goes from 0 ohms to infinite ohms when under vacuum or from some low resistance to a higher resistence when it switches?

My Vacuum Switch goes from a relatively low resistence (33 ohms) to a higher resistence (340 ohms) when vacuum is applied to it.  It switches when very low vacuum is applied to it.  Probably less than 1 in-Hg is what it takes to make it switch.  These resistences are not accurate since I was reading them through a long jumper wire but I was somewhat surprised that the resistance didn't go to infinity or create an "Open" when it switched.

Is the Purge Solenoid valve normally "closed" and then commanded "open" to allow the fumes to purge from the canister?  That is how I would think it would work.  Does anyone know how frequently the Purge Solenoid is commanded open?  I should be able to hook a vacuum gauge to the solenoid and see engine vacuum periodically, correct?

PS:  I just finished installing new KYB GR2 Struts and a Shock Tower Brace.  I'll try posting my pictures and comments about that soon. Thanks All.

I attached my hand actuated vacuum pump to the Vacuum Switch side of the Purge Solenoid and started the car. Vacuum read 0 in-Hg with the motor running. After about 2 minutes, the vacuum went to about 17 in-Hg and stayed there for at least twenty seconds until I shut the motor off. This tells me the PCM is commanding the solenoid and the solenoid is sending vacuum to the Vacuum Switch and then on to the Vapor Canister. There was essentially no resistance to flow from the canister when I hook up my vacuum pump to the line which goes to the canister.

I'm begining to suspect a vacuum leak between the canister and the vacuum switch.

But I would say the Purge Solenoid valve is normally closed. I still don't know if the Vacuum Switch is supposed to go to an "open" or just a higher resistance value, when under vacuum, than when it is not.

The purge solenoid IS normally closed until the PCM commands it on.

P0441 is NO FLOW during purge. Either the purge solenoid is bad, or you have a blockage somewhere. Hope this helps......

DTC P0441 Evaporative Emission (EVAP) System No Flow During Purge

Circuit Description
The EVAP purge valve allows manifold vacuum to purge the canister. The Powertrain Control Module (PCM) supplies a ground to energize the EVAP purge valve (purge ON). The EVAP purge valve control is Pulse Width Modulated (PWM) or turned ON and OFF several times a second. The duty cycle (pulse width) is determined by engine operating conditions including load, throttle position, coolant temperature and ambient temperature. The duty cycle is calculated by the PCM and the output is commanded when the appropriate conditions have been met:

•Engine coolant temperature above 25°C (77°F).
•After the engine has been running about 2 1/2 minutes on a cold start or 30 seconds on a warm start.
•The vehicle is operating in closed loop fuel control.
Canister purge commanded duty cycle varies according to operating conditions determined by mass air flow, fuel trim, and. intake air temperature.

Canister purge operation is also affected by throttle position.

•VIN 1 — Canister purge will be disabled if TP angle increases to above 33%. Canister purge will be re-enabled when TP angle decreases below 29%.
•VIN K — Canister purge will be disabled if TP angle increases to above 70%. Canister purge will be re-enabled when TP angle decreases below 66%.
The EVAP vacuum switch is a normally closed switch positioned in the purge line between the canister and the EVAP purge valve. The EVAP vacuum switch will open when vacuum increases to greater than 5 inches of water in the purge line. The PCM monitors the EVAP purge vacuum switch signal to determine of the evaporative emission control system is working properly. If the switch is closed (no purge flow) when the PCM is commanding the EVAP purge valve ON, DTC P0441 will be set.

Conditions for Setting the DTC
•No TP sensor, IAT sensor, MAP sensor, ECT sensor, or MAF sensor DTCs set.
•BARO reading is greater than 70 kPa.
•Engine Coolant Temperature is less than 114°C (237°F).
•Intake Air Temperature (IAT) sensor indicates an ambient temperature between 0°C (32°F) and 70°C (158°F).
•The difference between ECT and IAT is less than 10°C (18°F).
•Engine speed is between 650 rpm and 5000 rpm.
•Canister purge PWM is greater than 75%.
•EVAP vacuum switch remains closed (12 volts signal at the PCM).
•Above conditions for longer than 4 seconds.
Action Taken When the DTC Sets
•The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
•The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
Conditions for Clearing the MIL/DTC
•The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
•The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
•The DTC can be cleared by using the scan tool.
Diagnostic Aids
Check for the following conditions:

•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.

mine popped the other day 1441. put old iat sensor back in it went away.

joshuadalegrimes wrote:

mine popped the other day 1441. put old iat sensor back in it went away.

That makes no sense whatsoever