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Emissions Question

  • Thread starter Thread starter ACSPONY
  • Start date Start date Jan 9, 2007

ACSPONY

20+ Year Stangneter
Oct 10, 2004
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Jan 9, 2007
#1
  • Jan 9, 2007
  • #1
I'm looking at a '93 5.0, but the car failed the emissions test. I guess it passed the sniffer at speed, but it failed at low speed (700rpm?). I know the car was sitting for a while before the guy took it in for the test but what could have caused it to pass at speed but not in the lower rpm?
Thanks.
 
S

seijirou

Founding Member
Aug 15, 2002
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Jan 9, 2007
#2
  • Jan 9, 2007
  • #2
ACSPONY said:
I'm looking at a '93 5.0, but the car failed the emissions test. I guess it passed the sniffer at speed, but it failed at low speed (700rpm?). I know the car was sitting for a while before the guy took it in for the test but what could have caused it to pass at speed but not in the lower rpm?
Thanks.
Click to expand...

More important is what did it fail on, HC, NOx, or CO
 

dragnazz5.0

My "0" key d0esn't w0rk, s0 I have t0 use the zer0
Nov 19, 2005
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mooresville, nc
Jan 9, 2007
#3
  • Jan 9, 2007
  • #3
yeah...it could be anything. but if you know what it failed for we can narrow it down for you
 

ACSPONY

20+ Year Stangneter
Oct 10, 2004
711
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Ohio
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#4
  • Jan 9, 2007
  • #4
Sorry, I don't have the exact data from the test, I just know it passed at speed
 

jrichker

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#5
  • Jan 9, 2007
  • #5
How to pass emissions testing:

1.) Make sure all the emissions gear the car was made with is present and connected up properly. That includes a working smog pump and cats.

2.) Make sure that you have fresh tune up with spark plugs, plug wires, cap, rotor, fuel & air filters. An oil & filter change is a good idea while you are at it.

3.) 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/article...c-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/p-7208-equus-digital-ford-code-reader-3145.aspx– It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

4.) Post the codes and get help to fix them. Don’t try to pass with codes not fixed. Clearing the computer just temporarily removes them from memory, it doesn’t fix the problem that caused the code to be set.

5.) Be sure to do the testing on a hot engine. Drive for 15-20 minutes prior to taking the test to get operating temps up into the normal range. Do not shut off the engine while waiting for your turn on the test machine. An engine up to full operating temperature puts out fewer emissions.

High NO - high combustion temps - retard timing, check EGR for operation.
High CO - EGR isn't working - fix it.
High HC - fuel mixture too rich - check O2 sensors, smog pump, and cats. Clean MAF element. Do the ethanol thing as suggested.
 
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