# Failed Emissions Help



## euro.lo (Oct 19, 2010)

So I bought myself a 95 MK3 Golf. It has a 1.8L 8v in it, and I recently brought it in for an emissions test and failed. My NOx ppm was allowed to be 526. Unfortunately my car read out 791. 

_Pic of E-test_










_What I did in prep for the test_

-plugs checked 
-new oil/filter
-all new exhaust from the cat to the muffler with a res delete because it was rusted beyond repair. 
-I ran the test with half a tank of 91 octane instead of 89
-I put Bardall no smoke in with the oil.

_Sources of the Problem?_

-I looked over my e-test and they listed the motor as a 2.0l instead of a 1.8, not sure if that'll effect anything.
-My oil dipstick tube is cracked, and I've heard that that can cause issues. 

_What to do?_
I was given a pamphlet and these are the suggestions they gave:

-inoperative/ineffective EGR system
-Excessively lean air/fuel ratio
-Malfunctioning Catalytic convertor
-Excessive Spark Advance
-Faulty Thremostatic Air Cleaner System

I was thinking of just adjusting the timing a bit, I've been told that will work. I'm kind of at a loss at the moment. Any help would be great. Thanks! :beer:


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## euro.lo (Oct 19, 2010)

No one? Tough Crowd, BUMP!


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## dogzila22 (Apr 1, 2008)

maybe very lean mixture


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## Glegor (Mar 31, 2008)

vacuum leaks.. how does the car idle?

ive seen MANY vws with the catalytic converter still intact.. but there was no matrix inside.. just hollow..

advanced ignition timing can also do it, but not on this car.. the ECU controls timing..


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## ps2375 (Aug 13, 2003)

Glegor said:


> advanced ignition timing can also do it, but not on this car.. the ECU controls timing..


Not totally(I think), as this would be more like a digi motor, as far as timing would go. Remember, this is a 1.8L motor, not the 2.0 w/ the crank sensor. Have you checked the timing?


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## Seax_Smith (Jun 1, 2007)

the curb idle CO @ 0.01 seems really odd. Never dealt the ABA injection, but the 1.8's run about 1.0 CO when the mixture is set correctly (digi being digi, is altitude sensitive). Am not even sure what is in the Canadian cars.

The high NOx are an indicator of a lean/ too hot condition too.

As stated above - I've had CIS-E cars and digi cars pass idle emmisions test and dyno emmissions test with flying colors and hollow cats.

Wierd thing is the chart shows your AFR to be fraction too high, which would point to a vac leak as stated above. Then again cars rarely at 14.20 for extended periods.

When you start pushing the NOx down, expect the HC's to come up a bit. you have room for it, so it should be an issue.

HAve had experince with what seemed to be good, soft vac line getting a little sketchy at anything above idle speed. Ended up replacing all the soft vac lines with the 3 mm silicne stuff which did a lot for many little vac issues I could not find by spraying strater fluid at vacuum stuff on an idling issue.

Also replaced all the black rubber elbow fitting and the like with nylon "T"'s and elbows. Also check your hard. plastic, 1/8th inch vac lines for splits which are sealing at idle, but not at driving RPMS and opening when they start getting bounced around by the vibrations and bumps.


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## ps2375 (Aug 13, 2003)

Those canadian mkIII 1.8's are a "monomotronic", aka throttlebody injection.


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## euro.lo (Oct 19, 2010)

Wow! alot of good info in here. Thanks alot guys. I'm gonna try and check for vacuum leaks tonight, and the guy doing the emissions told me to try and back the timing off just a little bit, so it runs a little leaner.


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## Seax_Smith (Jun 1, 2007)

Lean may not be the way to go. Your HC's are low and your NOx are up. the last thing you want to do in lean it out a bit, increase the heat and increase your NOx and decrease the HC's.

May be wrong here, but if the vac leak isn't found, I'd retard the timing or richen it up just a fraction.

NOx, HC's and CO are all inter-related, to change one the other two have to change as well. You have room with your HC's to increase the unburnt fuel a little, which will decrease the the temp which will not allow as many NOx to form.

A good does of fuel system cleaner wouldn't hurt your cause as well. Have seen BG's K44 push more than a few cars through emmisions test when the car was just barely over a limit.

Lean = hotter, more NOx and fewer HC's.

Rich = cooler, fewer NOx and more HC's.

Really search for the vac leak with a can of starter fluid first, and be sure the rest of your ignition system and all the elec contacts are good-n-clean and solid, before you start tweaking the timing just to pass.

What would probably be best is to start at ground zero, reset the timing to spec, get teh AFR set to spec and then start looking for faults if you do n't pass. Most Mark II's haven't had the AFR adjusted (correctly) in a very very long time.


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## Glegor (Mar 31, 2008)

check for vacuum leaks, then check timing, and adjust if necessary. if its advanced, AND it has vacuum leaks, that would be your culprit.

like was stated, check with a can of starting fluid, or you can use propane too (with the right delivery method.


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## ziddey (Apr 16, 2006)

Seax_Smith said:


> the curb idle CO @ 0.01 seems really odd. Never dealt the ABA injection, but the 1.8's run about 1.0 CO when the mixture is set correctly (digi being digi, is altitude sensitive). Am not even sure what is in the Canadian cars.


The 1.0% CO is at the test port, pre-cat. 0.01% CO is exactly where it should be with a new cat.




> The high NOx are an indicator of a lean/ too hot condition too.
> 
> As stated above - I've had CIS-E cars and digi cars pass idle emmisions test and dyno emmissions test with flying colors and hollow cats.


I've never had any issues passing HC/CO with hollow cats. It's always the NOx that gets me, especially since my VW's don't have EGR. Does yours, euro.lo? I'm not familiar with your engine. If it does, it's definitely worth looking into.



> Wierd thing is the chart shows your AFR to be fraction too high, which would point to a vac leak as stated above. Then again cars rarely at 14.20 for extended periods.


Are you referring to the dilution values or are you gauging AFR based on CO/HC/NOx? The dilution values are just %co2. 14.20? I'm assuming you mean 14.7? Then again, with 10% ethanol being pretty standard now, 14.3 is the new stoich iirc.



> When you start pushing the NOx down, expect the HC's to come up a bit. you have room for it, so it should be an issue.


I've got over 6 failed smogs under my belt laugh::thumbdown::facepalm::facepalm, mainly knowing my cat is dead, but trying to get it to squeeze by. In the end, I was never able to get NOx down no matter what. I got to the point where it just a few ppm over the limit, but by then, my HC just exceeded. I could have played around more, but I just got another cat and passed. I keep that cat just for smogging now, so I shouldn't ever fail again..



OP, definitely look into vacuum leaks. Also, how long did you drive the car before the test? It makes a HUGE difference having the cat be up to temperature. One smogging, I drove 1 mile straight from my house to the test center. I was lucky to pass, since the max values were high that year, but my NOx from the first to second test (15 to 25mph) dropped from 1182ppm to 406ppm. HC dropped from 77 to 16, and CO from 0.45 to 0.05. 

I haven't ever really played around with throttle body injection, so this may not apply, but fuel distribution is key. If something is off with the spray pattern, you may end up with rich cylinders and lean ones. The lean ones will cause your high NOx.

But all in all, a bad cat is likely. Like mentioned, these cars tend to ace HC/CO even with a completely melted catalytic converter.

There isn't a way to adjust ignition timing I'm assuming, so the best you can do is make sure the cap, rotor, wires, and plugs are good. You can play with all the little things like I did, but after multiple attempts, I didn't get close enough. You can try copper plugs instead of platinum. Use a small gap. High octane fuel. Maybe fuel system cleaner, seafoam the intake, etc, and pray. Hell, even sucking a gallon of water through the intake will give a good steam cleaning and maybe reduce hotspots in the cylinder and get NOx down just enough.


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## euro.lo (Oct 19, 2010)

So, I checked all over, and the only thing I can come up with is the dipstick tube was cracked and leaking. I jimmy rigged a temporary tube that is sealing, but I'm not sure. . I am gonna try and reset the timing to factory specs, and pick up a new dipstick tube from the dealer. 

Since, I'm not sure, I recorded a video, here is the car idling, and a exhaust idle. Exhaust is stock with resonator removed. The hissing sounds alot more intense in the video than in real life. Let me know if you hear anything out of the ordinary. I might have used the propane method incorrectly. I just opened the bottle and let the propane leak out while I ran it along the lines. I've never checked for a vac leak before.


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## Seax_Smith (Jun 1, 2007)

ziddey said:


> The 1.0% CO is at the test port, pre-cat. 0.01% CO is exactly where it should be with a new cat.
> 
> ....


Good corrections. Thanks...

Smog is sort of a balancing act. NOx tend to be destroyed or altered in the front of the cat because of the heat. Many NOx are not so stable as molecules. The activation enery provided by the heat withing the cat converts a lot of NOx to N2 and O and O2. What happens with the O is what does us in. As long as it is hooking up with another O or a pair of stray H's were good, but when it starts finding N that isn't in the N2 form, or C, its over for smog.

Thing I have always found amusing is the bulk of what gets sucked into the intake is actually Nitrogen (N2) and Oxides of Nitrogen, like NO3 (sort of new meaning to "garbage in = garbage out")

"Cliff Notes" on running a gallon of water through the intake: http://home.comcast.net/~seaxsmith/_2gti/diy/diy_steam_clean.html


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## euro.lo (Oct 19, 2010)

ziddey said:


> I've never had any issues passing HC/CO with hollow cats. It's always the NOx that gets me, especially since my VW's don't have EGR. Does yours, euro.lo? I'm not familiar with your engine. If it does, it's definitely worth looking into.
> 
> OP, definitely look into vacuum leaks. Also, how long did you drive the car before the test? It makes a HUGE difference having the cat be up to temperature. One smogging, I drove 1 mile straight from my house to the test center. I was lucky to pass, since the max values were high that year, but my NOx from the first to second test (15 to 25mph) dropped from 1182ppm to 406ppm. HC dropped from 77 to 16, and CO from 0.45 to 0.05.
> 
> ...


 Well, I didn't drive it to the test, I told my dad to beat on it before he went for the test. I had the plugs re-gapped, and I changed all the oil, and I ran high test in it for the test. I might try picking up fuel cleaner as well tomorrow. I am pretty new when it comes to working on 8v's, so I'm learning alot! 



Seax_Smith said:


> "Cliff Notes" on running a gallon of water through the intake: http://home.comcast.net/~seaxsmith/_2gti/diy/diy_steam_clean.html


I'd be too scared to risk running water through the motor....


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## Seax_Smith (Jun 1, 2007)

euro.lo said:


> I'd be too scared to risk running water through the motor....


It's the same process used with SeaFoam, the GM top end cleaner, etc. It does seem wrong though, and I was very cautious when I did it.

I added the valve for the water becasue I wanted to be able to meter it very precisely and very slowly. Sucking some H2o through the intake is an old trick often used before head work to remove or soften up the carbon deposits.

If you are going to run some fuel system cleaner threw it, run the tank down to a quater or so before going for the smog test. Give the cleaner some time to work. A good long drive helps with add-to-the-tank fuel system cleaners, especially if you really get on the car after running for an hour or more.


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## euro.lo (Oct 19, 2010)

So, last night I tried to adjust the distributor and no dice. It was not moving. We used all kinds of wd-40, and tried hitting the base with a punch and a pry bar. It still would not move. So, I installed the dipstick tube, and figured I'd just go for it. I had it re-tested and it turns out there was barely any change. 

So, now I'm thinking I prob need a new catalytic convertor...


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## ps2375 (Aug 13, 2003)

Is timing out of spec? Does this management system have a special procedure to set timing?

The dizzy might be pinned like some ABA dizzies I have seen, a pin in the dizzy on either side of the dizzy hold down bolt. Did you completely remove the hold down bolt and then try to move it?


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## euro.lo (Oct 19, 2010)

I took the hold down bolt and bracket completely off, then cleaned everything as best as I could with a steel brush, blew it all out with the air compressor, and then lubed it heavily with WD-40, and after none of that worked, I tried to hit it with a punch and prybar to try and crack it loose...


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## ps2375 (Aug 13, 2003)

ps2375 said:


> Is timing out of spec? Does this management system have a special procedure to set timing?


 ?


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## euro.lo (Oct 19, 2010)

I decided to make my life easy. I brought it in today and I'm having a new catalytic convertor put on. I'm assuming it should breeze through now.


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## euro.lo (Oct 19, 2010)

Just to clear up this thread. Thanks for all the help. Turns out you guys where right, the cat was toast. I had it re-tested today and my NOX went from 790 to 48. :laugh: I should be free and clear to start driving it daily.


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## ziddey (Apr 16, 2006)

you should have the mixture tested as well. it'd be a shame to fail the next emissions only to find the cat got poisoned again


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## euro.lo (Oct 19, 2010)

emissions last 2 years here in Canada as long as it's under the same owner. I plan on getting rid of this car next time I need emissions, so I'm not too worried. It's just a beater until I finish up school.


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## xl600.mine (Jan 25, 2012)

*Same issue*

I'm actually having the exact same problem. However, I installed a new magnaflow cat about 4 months ago. I have a slight exhaust leak in front of the cat son't know if that would do anything. and i don't seem to have any vacuum leaks 

any help would be appreciated


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## Flashover1969 (Dec 14, 2011)

I have failed emissions test due to high Nox. What I did was drive the car until I only had a few gallons of gas left in the tank, found a gas station that sells e-85. Put in like 2 gallons of the e85, which is 85% ethanol. Re-took emissions test....passed with flying colors, I have done this more than once  
You can buy ethanol at the hardware store but it's like 8 dollars a gallon. 

After you pass the test go fill up with gasoline to dilute the ethanol more, so it won't be so corrosive to your fuel system. 

Do this at your own risk and until you can afford a new cat. I was scraping by for about 4 years sometime back and could never afford to have a new cat installed on my car.


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## mylesp (Jul 7, 2005)

Keep an eye on the throttle body mount on that car. I had one and couldnt for the longest time figure out why the exhaust was pinging. ( i never really looked too hard either) The mount had decayed and rotted in half lol even though there was only 130,000km on it. The throttle boddy was only held in place by the throttle cable and vacume lines ect. lol


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