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xanderdeg · Posted: Tue Nov 05, 2013 9:22 am Post subject: How do I pass emissions?

My hydrocarbons are too high at idle!

To pass the test should I just diddle with the mixture screw on the fuel distributor to lean it out enough to pass or is there something better I could do?

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

Get a proper CIS pressure tester kit and a wide band oxygen sensor and gauge. Adjust the CIS, ignition and idle properly and it should reach the proper A/F ratio to pass emissions.
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

xanderdeg · Posted: Tue Nov 05, 2013 9:29 am Post subject:

Is there a cheaper route? I'm not really excited to pay $200+ just to pass emissions unless I absolutely have to.

edit: but if it's what I have to do, I'll do it. Just wondering if there's a way to do it for a little bit cheaper.

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

Its part of owning a CIS-equipped car. You either buy/borrow the proper tools or pay someone who has them to do it for you.

"fiddling" will the adjustments without any way to get data from the changes could result in making the car run worse or potentially cause damage.

If you search here you'll see a link to how to build your own CIS pressure testing system.

WB02's aren't hard to find in newer cars, do a little search online and you may find some cheap ways to build a system you can connect to a laptop and view the data.

Or take it to a dyno shop to use their WB02 wand.

Think outside the box and you should be able to find a solution.
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Think outside the box, like, lean it out?
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

xanderdeg · Posted: Tue Nov 05, 2013 11:57 am Post subject:

Paul · Posted: Tue Nov 05, 2013 12:28 pm Post subject:

Are you running regular or high test?
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White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

!tom · Posted: Tue Nov 05, 2013 12:38 pm Post subject:

I'm guessing because they think it's a 924S you have a bit more leeway on your emissions readings.
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78 924 NA
5-lug

xanderdeg · Posted: Tue Nov 05, 2013 4:16 pm Post subject:

morghen · Joined: 21 Jan 2005 Posts: 9095 Location: Romania

Check the spark plug color for a rough reference of how the engine is runing right now.
Lean it out to the point it pulls like your jetta, then you'll pass. As you will lean it out you will also need to compensate with the TB air screw to keep the idle.
Be sure to write down how many turns you leaned it out so you can go back after you've passed.
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Supercharger and EFI kits
https://www.the924.com

xanderdeg · Posted: Tue Nov 05, 2013 6:32 pm Post subject:

staticsan · Joined: 19 Jan 2009 Posts: 450 Location: Sydney, Australia

A cat will lower your NOx, which I was told goes up when you make it leaner to make the hydrocarbons go down. I had to put a cat on my '82 924 even though it didn't technically "need" it because that was the only way to get it to pass emissions (NSW Australia).

You will find people who say a cat robs some of the HP, and others who say it doesn't.

Wade
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'82 British NA - Which I think I've been very lucky with!

ThomasJoseph315 · Guest

Your firing to late or running to lean.

Best bet is to go to a tune shop. I did after paying $400 in testing fees. They got it tuned in, in 10 mins. Passed that day.

Check your ignition system, coil, wires, plugs. Make sure they are all working right, then dump in some high octane fuel.

Also,. don't tune it then wait for another day to try and pass it. When weather changes, because we don't have a million sensors it will need to be passed the same day. I literally took mine from the tune dyno to the test dyno with the hood open, passed.

Also,. find a good tuner and someone to work with you. first few places I went the guys where just in it for the money, they could care less.

Paul · Posted: Wed Nov 06, 2013 10:14 am Post subject:

[quote="xanderdeg"]

!tom · Posted: Wed Nov 06, 2013 7:42 pm Post subject: