Emissions Test - FAIL!

hemi_fan · May 25, 2005

Hey guys, just took my car into the shop today to get it e-tested. Its been runnin real good since yesterday when I put new plugs, wires, distributor cap, and rotor on it... so i was hoping it would pass. Naturally, nothing works out properly. It didnt do so terribly tho, it failed one category. High rpms, it failed Hydrocarbons (HC). I was wondering what might be the cause of it? Cuz they want $75 for a diagnosis!!! So what would cause high HC at high rpm?

hemi_fan · May 25, 2005

GT89Mustang · May 25, 2005

Are you running all your emmissions stuff? Does it have a miss or run bad at high rpms? Do you have the numbers from your failure paper.

hemi_fan · May 25, 2005

Its running alright by the sound of it... when I changed the plugs, it had a bad plug (or wire or something), but now it seems to run better. Its got the smog pump + original h-pipe, everything is factory on it.

1912rpm... HC = 272 (max allowable is 66ppm)

89rdgt · May 25, 2005

this that would cause high HC is a missfire. It could be leaning out and missing, could be a ignition mis. You sure you didnt crack a plug or anything installing them? Can you tell us the rest of the reading co co2 o2 and nox if it has it.

hemi_fan · May 25, 2005

Sure, I re-created the exact chart... here it is;

I installed the plugs and wires myself, there seems to be no problems, except i did notice a slight 'tick tick tick' noise coming from the engine... not positive on that one.

hemi_fan · May 25, 2005

I figured it wasnt mis-firing if it passed HC at low rpm, but not high... cuz the HC woulda been high accross the board if it was mis-firing... maybe a timing issue? (i doubt that)... im new at these things. lol

jrichker · May 25, 2005

Step 1.) Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $33.

Step 2.) Post your results & we will try to help you fix them

Step 3.) Fix all the codes, now you can pass the emissions test.

5.0stang_gt · May 25, 2005

That ticking is prolly from a plug wire that came loose after the install. I just changed my plugs and I heard a ticking sound and i checked and it was the plug not all the way on. Just start from the begining to save some money.

hemi_fan · May 25, 2005

thanks guys, i'll deffinitely check teh plug wire, and i read that entire codes page, and i'll be pullin codes tomorrow also! Thx for the help guys, glad it was so quick cuz my temporary permit expires tomorrow!

mpswirl · May 26, 2005

Well heres some info Nox is high combustion temp, Co is partially burned fuel and Hc is Unburned fuel. hope it helps.

keith1991 · May 26, 2005

What would cause high NOX? Running without cats or hollowed out cats?

jrichker · May 26, 2005

keith1991 said:
What would cause high NOX? Running without cats or hollowed out cats?

More than stock spark advance, non-functioning EGR valve, higher than stock compression ratio.

hemi_fan · May 26, 2005

okay, pulled codes today... gave me 2 stored codes, no others...
29 - speed sensor failure ??
31 - EGR Valve

retested about 3 times, it kept giving me the same stored codes, no new codes. Checked all plug wires, did all tests KOER, KOEO, and the individual cylinder test... the KOER and cylinder tests gave no codes.

hemi_fan · May 26, 2005

Oh, ticking seems to be a slight exhaust leak either in the passenger-side header, or the donut between header/h-pipe on pass. side.

keith1991 · May 26, 2005

jrichker said:
More than stock spark advance, non-functioning EGR valve, higher than stock compression ratio.

I failed my emissions with almost 3 times the limit here in SoCal. Realized the timing was set at 14*.. Try again, this time bump the timing back down to 10*, getting an h pipe in which the cats are still good, new plugs, new wires, new cap and rotor. Hopefully I'll pass this time.

hemi_fan · May 26, 2005

Can i check the timing at home w/o any light/scope? cuz i dont have one lol

hemi_fan · May 26, 2005

ttt, this is killing me guys! I spent the last 10 months repairing and restoring my car!!! I got to drive it for a total of 10 days! Now its off the road again, someone please help! Im so frustrated!

89rdgt · May 26, 2005

With a code 31 your almost garunteeing your self a new Egr valve and EVP sensor. I have seen many of these issues and 99% need both valve and sensor. If your sensor was reading biasly low it would give extra egr at cruise and induce a slight miss hence high HC. Also if possible timing should be checked too and set to factory specs. If it was me I would replace both egr valve and EVP sensor because of the high failure rate.

hemi_fan · May 26, 2005

any ideas what that'll cost? and can i pick them up at the local parts store?

Emissions Test - FAIL!

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