| Author |
Message |
Chestercopperpot
Samba Member
Joined: March 26, 2017
Posts: 114
Location: Colorado
|
 Posted: Wed Oct 05, 2022 10:45 am Post subject: Failed Emissions Help |
 |
|
Second attempt in a few years and failed. I recently sorted FI and electrical issues to alleviate a hot start issue but still have lingering CO and HC. My HC is just out of spec whereas my CO is way out of the park. I'm thinking fixing the CO would bring in the HC but youre the experts.
(https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0)
Here is my emissions test from a few years ago:
Looking for Older numbers: I have older passing reports with 16. CO and 1. HC
Here is my recent emissions test:
Here are the numbers:
What I do know is:
I threw a plethora of parts at her in between tests. Including new AFM, throttle body, TPS switch, rebuilt injectors
I have NOT replace o2 sensor(although I have sorted wiring and see it sweep on VOM)
The charts both are fail ing but it does look as if my CO is WORSE than it was prior.
What I question:
My AFM has not been tuned per se, fresh out of the box from FIC. Could it be possible that it is at default or an incorrect position causing the large CO issues(it was new in both tests)?
My o2 sensor is relatively new 3.5k miles, do the graphs indicate failed o2?
Any help is appreciated, put a lot of time in this summer sorting the wiring and FI and am so close to the finish line. Just have to get pass this test
Last edited by Chestercopperpot on Wed Oct 05, 2022 11:18 am; edited 1 time in total |
|
| Back to top |
|
 |
r39o
Samba Polizei
Joined: May 18, 2005
Posts: 9800
Location: San Diego
|
| Posted: Wed Oct 05, 2022 11:10 am Post subject: Re: Failed Emissions Help |
|
|
Classic symptoms of lean or bad cat.
Did you get the cat really warm before your test? I mean run at 4-5K RPM on the freeway for like 5 miles. Then in low gear at high RPM until you got to the test station. Kept engine running before test? A cool cat is a classic way to fail.
High CO is a classic O2 sensor issue. Cheap O2 sensors do that.
My guess tends to be cat usually though. Old cats just do not work well.
Since you shotgunned a bunch of parts too, who really knows what it is off. Could be AFM too. Lots of chances to have issues with your particular set of circumstances.
I have no easy answer for you.
_________________
"Use the SEARCH, Luke" But first visit the Vanagon FAQ!
1990 Multivan EJ 22, Rancho trans 0.82 4th, Small Car front AC, CLKs w/ 215/65-16, homemade big brakes 303mm, Konis, Recaros, etc....
Click to see my ads for Cup holders, Subaru clutch fix and CLK wheels (no wheels currently) |
|
| Back to top |
|
|
brickster
Samba Member
Joined: January 05, 2004
Posts: 512
Location: CO, USA
|
| Posted: Wed Oct 05, 2022 11:19 am Post subject: Re: Failed Emissions Help |
|
|
Since you haven't replaced the O2 sensor, do you know how old it is? They are a wear item, and poor running can foul them earlier than their intended lifespan.
In addition to the stock single wire, unheated sensor option, you can also install a 3 wire, heated sensor mod on Digijets: https://www.thesamba.com/vw/forum/viewtopic.php?t=451793
If you're not in a rush to pass, I'd do the 3 wire mod as it allows for lambda compensation even if the exhaust gases aren't hot enough to allow the 1 wire sensor to send a signal. |
|
| Back to top |
|
|
Chestercopperpot
Samba Member
Joined: March 26, 2017
Posts: 114
Location: Colorado
|
| Posted: Wed Oct 05, 2022 11:27 am Post subject: Re: Failed Emissions Help |
|
|
| r39o wrote: |
Classic symptoms of lean or bad cat.
|
I raced her around and kept her warm prior to test(Rad fan was on), knowing I want it piping hot.
My van has been tested 6 times over the last decade. I have three passing tests( with 16. CO and 1. HC) from the early years. It is the most recent test that are failing.
Would not the HC be much higher with failed cat?
Knowing I had passing tests less than 1500 miles ago(5 years), does it make any more sense that the o2 failed versus the cat?
Also looking into the AFM adjustment, I have vague recollection of tuning my old(passing) unit to lower CO
Last edited by Chestercopperpot on Wed Oct 05, 2022 12:08 pm; edited 1 time in total |
|
| Back to top |
|
|
Chestercopperpot
Samba Member
Joined: March 26, 2017
Posts: 114
Location: Colorado
|
| Posted: Wed Oct 05, 2022 11:32 am Post subject: Re: Failed Emissions Help |
|
|
| brickster wrote: |
If you're not in a rush to pass, I'd do the 3 wire mod as it allows for lambda compensation even if the exhaust gases aren't hot enough to allow the 1 wire sensor to send a signal. |
I can see the logic in having a heated unit, Ill look into it. I see the linked article mentions idle test, my test is a driving dyno v. idle test. But, still see the advantage.
Technically, I have until next Saturday to retest but trying to cover 4 year expired plates to camp this weekend. May try to find a quick new single wire and look at AFM to attempt to retest tomorrow.
Would too advanced timing have any correlation? |
|
| Back to top |
|
|
Igeo
Samba Member
Joined: September 25, 2018
Posts: 888
Location: Oakland, CA
|
| Posted: Wed Oct 05, 2022 2:59 pm Post subject: Re: Failed Emissions Help |
|
|
Yes.
Too much advance will increase NOx in particular.
I run 45 to 50 degrees at 3,000 rpm, but dial it back to 35 degrees prior to the test.
_________________
1987 Westfalia 2.1 WBX Manual |
|
| Back to top |
|
|
Chestercopperpot
Samba Member
Joined: March 26, 2017
Posts: 114
Location: Colorado
|
| Posted: Wed Oct 05, 2022 3:33 pm Post subject: Re: Failed Emissions Help |
|
|
| Igeo wrote: |
Yes.
Too much advance will increase NOx in particular.
I run 45 to 50 degrees at 3,000 rpm, but dial it back to 35 degrees prior to the test. |
Cool. Nox is just over and CO is obnoxious ... I'm at 35 deg now, can I pull back more for the test?
Update:
O2 sensor replaced (bosch 11047), looks shiny anyway.
I tested the 02 / AFM via lead on o2 and ground through a digital VOM. I can see the voltage drop below .5 volts on throttle.
The voltage from the unit at idle, rises during the test from .8 gradually to .9990 where it remains steady, sometimes over 1. v. until the throttle is opened
Is this of concern from a new unit? I have read to dial it to be around .8 volt, but the stoich chart points to 1.0 as 14.72? have a newly rebuilt AFM and I attempted to lower the o2 voltage too .8 v and I get absolutely no change from turning the AFM allen bolt. Is this a concern? I would think I could affect it by turning.
Going to retest in the AM, then assume cat if I fail again. Unless wiser heads prevail.
Last edited by Chestercopperpot on Wed Oct 05, 2022 6:17 pm; edited 1 time in total |
|
| Back to top |
|
|
Howesight
Samba Member
Joined: July 02, 2008
Posts: 3274
Location: Vancouver, B.C.
|
| Posted: Wed Oct 05, 2022 3:43 pm Post subject: Re: Failed Emissions Help |
|
|
| r39o wrote: |
Classic symptoms of lean or bad cat.
Did you get the cat really warm before your test? I mean run at 4-5K RPM on the freeway for like 5 miles. Then in low gear at high RPM until you got to the test station. Kept engine running before test? A cool cat is a classic way to fail.
High CO is a classic O2 sensor issue. Cheap O2 sensors do that.
My guess tends to be cat usually though. Old cats just do not work well.
Since you shotgunned a bunch of parts too, who really knows what it is off. Could be AFM too. Lots of chances to have issues with your particular set of circumstances.
I have no easy answer for you. |
I disagree that the OP's CO and HC readings are a sign of "lean". I expect this was a reference to a lean mixture. High carbon monoxide and hydrocarbon readings signify a rich mixture of exhaust gases.
But that is not the end of the story. If one cylinder has a constant or intermittent miss, then this floods the exhaust flow with excess oxygen. If the oxygen sensor is functioning properly, the ECU then compensates for the excess oxygen by adding fuel trim. The oxygen sensor doesn't care what the actual AFR (air/fuel ratio) is - - it only measures oxygen concentration.
The lambda system (essentially, the O2 sensor plus ECU programming) in the WBX is based on an assumption that there are no intake system leaks, no exhaust leaks, and that the ignition system is working properly by delivering useful spark at the right time. (However, the spark timing will have to be way off before it affects HC or CO levels.)
A common problem in the WBX is a misfiring cylinder at idle or low-throttle settings. The misfire causes the excess oxygen in the exhaust flow, which results in the Lambda system adding fuel, as well as the excess unburnt fuel from the misfire event itself. The excess fuel is partially burnt in the exhaust system, but poorly burnt, which is what makes the CO go out of spec.
What to do?
1. Check ignition system to rule out misfires caused by poor spark;
2. Replace the oxygen sensor and sort the wiring;
3. Check for intake system leaks, (including at the breather tower) and repair as needed;
4. Check for exhaust system leaks. These leaks can result in ambient oxygen being sucked in and measured by the oxygen sensor, which then causes the lambda system to add fuel - - thus raising HC and CO
5. After doing the above, replace you catalytic converter. Why later? So you don't ruin the new one. This is the single most important part of passing emissions testing because a new CAT will clean up a LOT of problems.
I am adding an edit as I just saw the post above. I can't tell from the description of the O2 sensor readings whether the testing was set up correctly. However, if the testing was set up correctly, then you have a problem.
When the coolant temp sensor senses that the engine is warmed up, the lambda system commences operating. It may be that your ECU is not receiving that coolant temp sensor reading properly. The lambda system should adjust the fuel trim at least once per second and it should flip between around .4 volts to .6 volts or thereabouts, repeatedly. In your reported readings, there is only a gradual slide towards a rich mixture.
_________________
'86 Syncro Westy SVX |
|
| Back to top |
|
|
Chestercopperpot
Samba Member
Joined: March 26, 2017
Posts: 114
Location: Colorado
|
| Posted: Wed Oct 05, 2022 6:15 pm Post subject: Re: Failed Emissions Help |
|
|
| Howesight wrote: |
I am adding an edit as I just saw the post above. I can't tell from the description of the O2 sensor readings whether the testing was set up correctly. However, if the testing was set up correctly, then you have a problem.
When the coolant temp sensor senses that the engine is warmed up, the lambda system commences operating. It may be that your ECU is not receiving that coolant temp sensor reading properly. The lambda system should adjust the fuel trim at least once per second and it should flip between around .4 volts to .6 volts or thereabouts, repeatedly. In your reported readings, there is only a gradual slide towards a rich mixture. |
Would the throttle switch being at idle make a difference. The o2 does fluctuate once I open the throttle. If dips below to the low spectrum, below .5 volts and back to .9 when I let off. I thought this was a function of the tb switch>?
I'll report back, plan to test with new o2 and retarded timing tomorrow. Not wanting to buy a 1200 cat!! |
|
| Back to top |
|
|
Chestercopperpot
Samba Member
Joined: March 26, 2017
Posts: 114
Location: Colorado
|
| Posted: Thu Oct 06, 2022 5:03 pm Post subject: Re: Failed Emissions Help |
|
|
Failed again!! New o2 and cat cleaner, retarded timing didn't help.
The only thing left to replace at this moment is the cat... |
|
| Back to top |
|
|
do.dah
Samba Member
Joined: August 27, 2015
Posts: 444
Location: Washington
|
| Posted: Thu Oct 06, 2022 7:27 pm Post subject: Re: Failed Emissions Help |
|
|
| Um,, in my experience, IF cat cleaner does anything, it'd take a coupla hundred miles, and possibly a 2nd bottle with another coupla hundred miles. |
|
| Back to top |
|
|
Abscate
Samba Member
Joined: October 05, 2014
Posts: 22639
Location: NYC/Upstate/ROW
|
| Posted: Fri Oct 07, 2022 6:29 am Post subject: Re: Failed Emissions Help |
|
|
Get the new cat. Make sure it’s OE and will pass visual.
For every one guy prancing on YouTube about Oxicat there are 999 others who got suckered into buying it. The only use for this is adding it to your brake fluid to enhance AC performance.
Why do why Cheerios taste like pee?
_________________
.ssS! |
|
| Back to top |
|
|
Chestercopperpot
Samba Member
Joined: March 26, 2017
Posts: 114
Location: Colorado
|
| Posted: Fri Oct 07, 2022 9:43 am Post subject: Re: Failed Emissions Help |
|
|
I did realize I was putting my faith in snake oil and had little hope. Most of these products state that they are for maintaining versus fixing and are more suited for newer catalyst maintenance. I did see a devide that plugs into your o2 bung and allows you to fog out your cat a the source but I did felt suckered putting it. But $40 versus $1200....
If I had and extra $1200 laying around a new cat would be one of my first purchases, unfortunately I do not.
Im hoping that I am able to get a loaner to get buy and may have one arranged. |
|
| Back to top |
|
|
Chestercopperpot
Samba Member
Joined: March 26, 2017
Posts: 114
Location: Colorado
|
| Posted: Tue Oct 18, 2022 11:08 am Post subject: Re: Failed Emissions Help |
|
|
| Abscate wrote: |
Get the new cat. Make sure it’s OE and will pass visual.
Why do why Cheerios taste like pee? |
So this is the plan.
I'm in deep and have talked to the state office that is in charge of the process and am going thru some steps that will lead to exemption or passing test.
Today was my smoking vehicle and vehicle evaluation where they inspect the emissions controls and fuel system to "evaluate the issue".
I have a print out stating my o2 sensor was sooty on threads causing exhaust leak and lean running and that the fuel injectors "appear new but could be incorrect or cheaply made."
O2 sensor was replaced 2 weeks ago using supplied antiseize, maybe I need more(I dont feel leak)...also, the injectors are OEM and were serviced recently by MR Injector.
They did all this while, supposedly, on a 5 gas analyzer. They do not dyno this process and provide no readings or graph to use for reference. I failed the O2 sensor, spark and injector portion of the test. They stated it runs horribly(best it's been under me 8+ years), and urges off idle and for this reason they failed me. I believe this issue to be caused by retarding the ignition to test or, could by AFM adjustment be out of whack causing issues with gas analyzer?
| Quote: |
| I also snipped this quote from WildThings: "On the 1.9 the cut on and cut off speeds are the same causing the engine to surge. VW fixed this problem on the 2.1 by having a cut off speed that is much higher than the cut on speed. If your throttle shaft bushing are getting sloppy or if you have other vacuum leaks that are leading to an above spec idle speed then this form of surging is common. With a manual tranny is is an absolute PITA." |
My 1.9 has done this surging for ever between idle and 1200 rpms, I can tune it out some with timing (mostly) , I also have a shoebox tps and new throttle body, AFM in an attempt to fix this issue to no avail. (I have no real issues with it, but others seem to )
Anyway, I have a new federal cat and will use it to test this week. I have intel that suggests that the technicians in-charge of the "basic" drive test are not educated in the differences between catalysts and just need to show passing parameters.
The inspector technicians who preform the "vehicle evaluation" I had done today, DO have the ability and education to inspect catalyst. The state official even asked if I had a subi conversion...
I was bummed I didn't get back on the rollers to see a print out. In last attempt and to just see what happens I did tiktok/youtube repair and physically soaked and cleaned the cat. Surprisingly, the differences in appearance were night and day. The old degreased and cleaned cat looks visibly cleaner than the brand new one I have. I know it is probably bunk and I am semi-shamed mentioning it but would have been cool to see the results from the dyno. I did it for science not expecting real results but was curious.
I assume gas analyzers give %'s ? Would have been interested to see if there were any change, even minor.
Next step is new federal cat install and retest. |
|
| Back to top |
|
|
Xevin 
Samba Member
Joined: January 08, 2014
Posts: 7623
|
| Posted: Tue Oct 18, 2022 11:55 am Post subject: Re: Failed Emissions Help |
|
|
Can you do a compression test? It would be a waste of time if your cam is old and worn that no amount of dicking and tossing parts on will allow it to pass. Cheap and easy test.
_________________
Keep on Busin'
| 67rustavenger wrote: |
GFY's Xevin and VW_Jimbo!  |
| Clatter wrote: |
| Damn that Xevin... |
| skills@eurocarsplus wrote: |
I respect Xevin and he's a turd  |
| SGKent wrote: |
My God! Xevin and I 100% agree  |
|
|
| Back to top |
|
|
Chestercopperpot
Samba Member
Joined: March 26, 2017
Posts: 114
Location: Colorado
|
| Posted: Tue Oct 18, 2022 12:11 pm Post subject: Re: Failed Emissions Help |
|
|
| Xevin wrote: |
| Can you do a compression test? It would be a waste of time if your cam is old and worn that no amount of dicking and tossing parts on will allow it to pass. Cheap and easy test. |
I've dicked around and threw on most all the parts already. I do believe the cam to be fine, but will look again if I cant get the issue to go away.
Attached is video link showing me apply steady foot pressure with strange rev results. This is an older video and it is not as bad as video currently. I believe I can tune this out with advance and will try today. The technician stated it was bad injectors.
https://i.imgur.com/4bzJ8ZZ.mp4
EDit: lack of compression shows the worn cam? |
|
| Back to top |
|
|
Xevin
Samba Member
Joined: January 08, 2014
Posts: 7623
|
| Posted: Tue Oct 18, 2022 12:30 pm Post subject: Re: Failed Emissions Help |
|
|
| Chestercopperpot wrote: |
| Xevin wrote: |
| Can you do a compression test? It would be a waste of time if your cam is old and worn that no amount of dicking and tossing parts on will allow it to pass. Cheap and easy test. |
I've dicked around and threw on most all the parts already. I do believe the cam to be fine, but will look again if I cant get the issue to go away.
Attached is video link showing me apply steady foot pressure with strange rev results. This is an older video and it is not as bad as video currently. I believe I can tune this out with advance and will try today. The technician stated it was bad injectors.
https://i.imgur.com/4bzJ8ZZ.mp4
EDit: lack of compression shows the worn cam? |
I’ve seen and experienced a Vanagon 1.9 wbx that could not pass emissions by mechanics who deal with local emissions testing and helping clients to pass. One van drove beautifully on the street but only had 60 on #1 40 on #3. #2 and # 4 had 150 on each. A leak down test also confirmed the engine was not going to pass emissions. The low compression on #1 and #3 were clues the cam was done for.
I’m not a talented mechanic. I know some things and a couple of my really good friends do this for a living. I only offered the advice because I’ve seen it and it’s not expensive to check out. Usually you can borrow a tester from the local FLAPS. Good luck and keep us updated.
The engine was just old and tired
_________________
Keep on Busin'
| 67rustavenger wrote: |
| GFY's Xevin and VW_Jimbo! |
| Clatter wrote: |
| Damn that Xevin... |
| skills@eurocarsplus wrote: |
| I respect Xevin and he's a turd |
| SGKent wrote: |
| My God! Xevin and I 100% agree |
|
|
| Back to top |
|
|
skills@eurocarsplus
Samba Peckerhead
Joined: January 01, 2007
Posts: 16859
Location: sticksville, ct.
|
| Posted: Tue Oct 18, 2022 1:03 pm Post subject: Re: Failed Emissions Help |
|
|
my .02
your CO is off the chart. this has to be running eye watering pig rich
co2 is maximized at stoichiometric burn, if it were low, that could indicate rich or lean, but it's sky high
NOx is produced in significant amounts in lean conditions and requires high gas temperatures usually on seen under loaded conditions. Little is produced at rich mixtures, therefore I believe your base tune is pig rich
even with a dead cat, these numbers need to be lower. not saying you don't need one, but i would get the readings way down before i bought one
how is the ECT and thermostat? is this running too cold?
_________________
| gprudenciop wrote: |
my reason for switching to subaru is my german car was turning chinese so i said fuck it and went japanese....... |
| Jake Raby wrote: |
| Thanks for the correction. I used to be a nice guy, then I ruined it by exposing myself to the public. |
| Brian wrote: |
| Also the fact that people are agreeing with Skills, it's a turn of events for samba history |
|
|
| Back to top |
|
|
Chestercopperpot
Samba Member
Joined: March 26, 2017
Posts: 114
Location: Colorado
|
| Posted: Tue Oct 18, 2022 3:46 pm Post subject: Re: Failed Emissions Help |
|
|
| Xevin wrote: |
I’ve seen and experienced a Vanagon 1.9 wbx that could not pass emissions by mechanics who deal with local emissions testing and helping clients to pass. One van drove beautifully on the street but only had 60 on #1 40 on #3. #2 and # 4 had 150 on each. A leak down test also confirmed the engine was not going to pass emissions. The low compression on #1 and #3 were clues the cam was done for.
I’m not a talented mechanic. I know some things and a couple of my really good friends do this for a living. I only offered the advice because I’ve seen it and it’s not expensive to check out. Usually you can borrow a tester from the local FLAPS. Good luck and keep us updated.
The engine was just old and tired |
I have tested compression and have ability too again, but didnt factor it into the issue as it is not poor running
| skills@eurocarsplus wrote: |
my .02
your CO is off the chart. this has to be running eye watering pig rich
co2 is maximized at stoichiometric burn, if it were low, that could indicate rich or lean, but it's sky high
your base tune is pig rich
even with a dead cat, these numbers need to be lower. not saying you don't need one, but i would get the readings way down before i bought one
how is the ECT and thermostat? is this running too cold? |
ECT new, have three spares too. Thermostat is new and was replaced at h20 pump ~100 miles ago.
Not running cold, runs in spec and 2-speed fan cycles, etc. I dont doubt I could be running rich, they suspected injectors but they have been replaced and tuned.
I also wondered if a new cat would be able to scrub that much CO.
What else could cause me to run rich. Can the AFM cause the richness? It is newly rebuilt and seems to be the culprit of my idle issue, feels like the arm is stuck for a bit. I have yet to open it up too see.
Here are images of my sooty, leaky, o2 sensor.
I see no soot, nor experience leaks
Will attach videos of this. |
|
| Back to top |
|
|
Californio
Samba Member
Joined: May 17, 2007
Posts: 1301
|
| Posted: Wed Oct 19, 2022 8:16 am Post subject: Re: Failed Emissions Help |
|
|
| Don't take this wrong, but if you're in Fort Collins, there's a pretty good Vanagon shop there too...maybe an hour of their time would be worth it... |
|
| Back to top |
|
|
|
