Resolved 1G Failed Emissions (Colorado)

[dwb]

After a miserable hour in line and rude staff who couldn't drive it, I ended up barely failing my emissions test.
TBH, I didn't do anything to prepare. In the past I have disconnected the wastegate actuator so it couldn't boost on the rollers and on occasion I have used low octane gas.

Here's the results. NOx just barely over the limit. Immediately after the test I took it for a drive and recorded the attached datalog. I haven't even looked at the log yet, nor researched what high NOx could be caused by. I thought I'd get this up here and then do my research. Whatcha guys think?

Edit: So I immediately see an issue with my idle switch. Not sure if that would affect emissions, but probably not helping.

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[Drewpy Dawg]

High Nox is usually caused by the EGR valve or catalytic converter. You may want to pop your EGR valve off and make sure the passages aren’t plugged with carbon (I had that happen once) and use a hand vacuum pump to make sure it’s opening and closing and holding vacuum. If you’re able to go for the re-test at a non-busy time give the car a good workout on the road (the old “Italian tune-up”) before the test to make sure everything is up to good operating temp.

 

[dwb]

Egr is blocked off. It's passed before like this. But the cat is original. That's my fear right now.

Lol, yeah I'd love to get there and not have to wait. 8:15am was way busier than I thought it would be. Idling for an hour can't be good.

For reference, here's what the results were last time I tested.

1991 TSi AWD

Do you have your Injector Battery Voltage offsets correct since it seems to get worse the more load you put on the electrical system.Interesting, I've never heard of that. Can you elaborate?

www.dsmtuners.com

Going to install new plugs and wires, change the oil, and disconnect the wastegate. Its possible I could make the EGR work again.

 

[dwb]

How is this even possible? I took it back today after an oil change, new plugs/wires, fixed a couple small boost leaks, and wired open the wastegate. It failed WORSE than last week! I didn't even have to wait an hour in line, maybe 30 minutes this time. It should have been nice and hot too.
HC GPM: 1.7699/1.2
NOx GPM: 3.5218/3.0

The morons running the dyno stalled it at least half a dozen times and had to restart the test over and over. They probably contaminated the CAT and didn't give it time to clear. I literally called them out on it and they told me to F-off and buy a new car.

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[dwb]

A new catalytic converter solved this.
Being in Colorado, I couldn't just buy any old cat. It had to be CARB compliant AKA California legal. $600 just for the cat. But ya know, to keep a DSM on the road takes some sacrifices. I guess 280k+ miles and 35 years out of the original isn't too shabby.
Anyway, take a look a these numbers now

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[steve]

Congrats! Maybe you could teach them how to spell Eagle
Every time I failed here in Illinois it was a lazy O2 sensor. The last and final test I even passed with no cat. I was expecting to have to go back with it on but it didn't happen.

I had to smog my red TT a couple of times while I was stuck in Boulder year round and the testing location by the airport never had a long wait, plus the guys knew how to drive a 6 speed AWD. I'd have to pay them cause it was for out of state plates but they never gave me any hassle.

 

[dwb]

Congrats! Maybe you could teach them how to spell Eagle
Every time I failed here in Illinois it was a lazy O2 sensor. The last and final test I even passed with no cat. I was expecting to have to go back with it on but it didn't happen.

I failed once before with a dead O2 sensor in the Talon and gas cap failure once in the Highlander.
Requirements here must be much more stringent than IL. No way could I get away catless.
Fortunately I didn't have to wait this time. Got right in and they only stalled it one time. Different test facility though.

 

[steve]

I can't find the paperwork ATM but in Illinois they were pulling all the rollers and all the ODB1 cars had to pass one more time and if they did they were grandfathered for no more testing. I squeeked by on the HC but everything else was great. I took the win and went home.