I can't pass emission tests.

How to pass emissions testing:

High NO - high combustion temps - retard timing, check EGR for operation.
High CO – Rich condition - fuel pressure too high, check O2 sensors, replace air filter, Clean MAF element.
High HC – Lean misfire, vacuum leak, common misfire due to worn or weak ignition system components. On rare occasions, an overly rich mixture may be the cause. Do the ethanol/E85 fill up as suggested.
High CO & HC - Cat converters, smog pump, and smog pump controls.

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…Codes may be present in the computer even if the Check Engine light isn’t on.

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/





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.



89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.




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 less than $30 or so at AutoZone or Wal-Mart.

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.

i cant really give any input here, but thats odd how the numbers like doubled, damn. Im in the same boat as you, im trying to pass emissions to...if you figure out the problem let us know

good luck dude

Well it seems my 93 is a smog monster and Ca wants me to smog every year. To top it off I have to go to a test only station. Here is what I do.

Back timing off to 4 degrees.
Change oil and filter. Clean MAF sensor.
Tune up, plugs, cap rotor and if your O2 sensors are older then 50k replace them too. Get bosch, its worth the added cost. Replace air filter. Drive car for a long freeway run to get the compute tuned to your new setup.

Then run the tank down to almost empty and buy 91% rubbing alcohol. I buy 12, 16 ounce bottles and pour it in the the almost empty tank.

Take the car to the smog shop and while waiting leave the engine running. This gets the cats hot, the hotter the better they work. On my exhaust I have a leak around the output of the muffler which when they test lessens the amount of exhaust that enters the right tail pipe. I always just pass!

Morel to the story, in CA do not modify your ride.

Allen

you really put rubbing alcohol in your tank? wow i have never heard that one lol

Are you running Mass Air or Speed Density? Some 88 Calf. cars had Mass Air. The reason I ask is because the 70mm throttle can't be helping your situation if the car hasn't been converted to mass air. Having a 70mm throttle body on a stock motor with a stock MAF, stock EGR spacer, and Stock Intake hurts more than it helps. I'm not sure whether this has anything to do with your high emissions, but if it were me, I would pull the 70mm throttlebody and throw on the stock unit and retest for emissions. It certainly can't hurt.

[I know I'm running rich as there is a slight fuel smell coming from the exhaust, I just don't know how bad. My problem is, why the big jump in numbers when I put on cats and why did it run the worse when the brand new cats were put on it? Only thing I can think of is my O2 sensors are going bad any thoughts guys.[/QUOTE]

I can tell you this. I was using a liberal amount of carb cleaner in my car at fast idle to get the varnish out of the throttle body. Probably used like 1/2 a regular can. In a couple minutes I smelled something burning - it was the undercoating on the floor boards starting to ignite from the cherry red Cat...holy cow.

Had to get the hose to put out the smoldering mess.

Story number 2: I had a turbo car that I just got back from the shop and when I got on it the hose popped off the turbo making it run rich. Cat got cherry red hot in 1/2 mile to my driveway and set fire to the accumulated oil from a previous turbo failure...that was just plain scarey. Used a weed sprayer to dose the flames.

Moral to my stories is that the cat doesn't work with fuel on it. It just becomes a furnace.

Lean the mixture up via new O2 sensors if yours are old. Most cars fail emissions because of the gas cap not holding pressure.

Newer cars don't have to be tested running they just check for codes in the computer which is a good thing. I think '96 is the year they stop running the vehicle with the hoses.

When it comes to throttlebodys, bigger is not always better. Besides, I believe the cobra opening is only 64 1/2mm, so using a 70mm throttle does absolutely no good. In fact, it hurts your engines performance because it disrupts the smooth airflow to your intake when it meets the "mismatch in opening sizes". Even with a ported intake and ported heads, I wouldn't go any larger than a 65mm throttlebody. Above all, I certainly wouldn't change the throttlebody size without converting to Mass Air first.

WhiteThunder said:

This is on an 88 5.0.I know I'm running rich as there is a slight fuel smell coming from the exhaust, I just don't know how bad. .

Click to expand...

One other thought comes to mind. If your fuel injectors are original - one or more might be leaking. One constantly spraying injector can really raise rich issues. Take a good look at your plugs when you do the tune up to see which one are black (or wet). If you have the time you could pull the injectors to see if they are leaking.

twistedwankel said:

One other thought comes to mind. If your fuel injectors are original - one or more might be leaking. One constantly spraying injector can really raise rich issues. Take a good look at your plugs when you do the tune up to see which one are black (or wet). If you have the time you could pull the injectors to see if they are leaking.

Click to expand...

Good idea, but there is a simpler way to test injectors...

Cylinder balance test:
Warm the car's engine up to normal operating temperature. Use a
jumper wire or paper clip to put the computer into test mode. Start
the engine and let it go through the normal diagnostic tests, then
quickly press the throttle to the floor. The engine RPM should exceed
2500 RPM's for a brief second. The engine RPM's will increase to about
1450-1600 RPM and hold steady. The engine will shut off power to each
injector, one at a time. When it has sequenced through all 8 injectors,
it will flash 9 for everything OK, or the number of the failing cylinder
such as 2 for cylinder #2. Quickly pressing the throttle again up to
2500 RPM’s will cause the test to re-run with smaller qualifying figures.
Do it a third time, and if the same cylinder shows up, the cylinder is
weak and isn’t putting out power like it should. See the Chilton’s Shop
manual for the complete test procedure

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/





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.



89 through 95 cars have a working Check Engine light. Watch it instead of a test lamp.



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 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.

Do a compression test on all the cylinders.
Take special note of any cylinder that shows up as weak in the cylinder
balance test. Low compression on one of these cylinders rules out the
injectors as being the most likely cause of the problem. Look at cylinders
that fail the cylinder balance test but have good compression. These
cylinders either have a bad injector, bad spark plug or spark plug wire.
Move the wire and then the spark plug to another cylinder and run the
cylinder balance test again. If it follows the moved wire or spark plug,
you have found the problem. If the same cylinder fails the test again,
the injector is bad. If different cylinders fail the cylinder balance test,
you have ignition problems or wiring problems in the 10 pin black &
white electrical connectors located by the EGR.

How to do a compression test:
Only use a compression tester with a screw in adapter for the spark
plug hole. The other type leaks too much to get an accurate reading.
Your local auto parts store may have a compression tester to rent.
If you do mechanic work on your own car on a regular basis, it would
be a good tool to add to your collection.

With the engine warmed up, remove all spark plugs and prop the
throttle wide open, crank the engine until it the gage reading stops
increasing. On a cold engine, it will be hard to tell what's good &
what's not. Some of the recent posts have numbers ranging from
140-170 psi. If the compression is low, squirt some oil in the cylinder
and do it again – if it comes up, the rings are worn. There should be
no more than 10% difference between cylinders. Use a blow down
leak test (puts compressed air inside cylinders) on cylinders that
have more than 10% difference.

See the link to my site for details on how to build your own blow
down type compression tester.

How long did you run the NEW cats before testing?

The efficiency will increase over the first couple hundred miles...


good luck,
jason

i heard to add 2 bottles of alcohol to about a quarter tank to a half tank of 91 oct gas. wonder if you could pull an injector wire an have it pass only putting out the gases of a 7 cyl

lang williams said:

wonder if you could pull an injector wire an have it pass only putting out the gases of a 7 cyl

Click to expand...

The ecu would see all the excess air from the dead cylinder, and decide that the bank was lean.
To fix the lean condition, the ecu would start dumping excess fuel in the other 3 cylinders...
Won't work...




jason