Emissions
 

I live in Missouri, and Im having trouble passing the emissions testing. For those not familliar that could maybe shed some light ill explain. THere are 3 catagories to pass: Hydrocarbons, Carbon Monoxide, and Oxides of Nitrogen. I am currently passing Hydro. and Carbon mon. Does anyone have an idea of what i should check or adjust to get the level within the limit?

secret 'passing' info
 

WEE-WEE, mon-sheri, (that thar's french, for yea)

Scan in your failed report so I can look at the #s.

(see my profile for "who I am, and what I do").

I dont have a scanner but i took a picture of the graphs. Green line is the vehicle speen, black line is the test readings, and straight black line is the maximum level. First graph is hydrocarbons, second is Carbon monoxide, and last is oxides of nitrogen. Any other info you need to know?

Well, that's too blurred to see, and here they have a different printout.
Can you tell me what the max allowed is, and what yours measured, for each of the 3 catagories??

ie: HC (ppm) max 106, yours 99
CO (%) max 70, yours 0.14
NO (ppm) max 762, yours 1000

If your NOx was over the limit, there's a good chance the EGR system is the trouble. These EGR valves are usually tough, and not the cause. The passages get clogged up, and that needs checking. The EGR valve transducer goes bad more often than the valve.

Read the last 2 posts in the FAQs section, "EGR System Facts"

HC: Max 0.8, Mine .4980
CO: Max 15.0, Mine 9.3472
NOx: May 2.0, Mine 5.3327

Looking at the graph i got, it looks like the NOx levels spike under accelleration.

Yep, Sounds like the EGR system is not working. Read the last part of my last post.

Remove the little metal cover (with 4, 10mm head bolts) that is on top of the intake manifold. That is an access cover to help clean out the EGR passages. I bet its plugged.

And I bet the EGR cooler is plugged too. Its a bitch to remove, as it is on the back side of the head. The rest is easy to clean out.

Ill look in the intake manifold passage, but i know for a fact that the passage on the back of the head is clean. (This car has pretty much been overhauled. Engine has been completely dissasembled and rebuilt). If the intake manifold passage is clear what would the next thing be to check? What exactly is a transducer and what does it do?


PS thanks for sharing your knowledge!

The transducer is actually a vacuum modulator. Pg EC-12 in TSRM.

Apply vacuum directly to the EGR valve while idling the engine. (you can use a spare vacuum hose and your mouth).

If valve is good, and passages are clear, the engine will stumble hard, and may die, as you will be creating a big vacuum leak, and diluting the fuel mixture a whole lot.

If engine does not stumble hard, then either the valve is not working, or the passages are plugged (somewhere along the way).

Well the passages in the intake were clogged up, so i cleaned them out. My buddy did some testing of the vaccume system. Some of the hoses were on wrong (but i used the picture off the forum here, so apparently thats not right). Yes the Vaccume mod was bad. I had another one here that we put on. We then started getting EGR flow through the tube on the back of the engine to intake manifold. But it still didnt pass the test. Here are the new numbers

HC Max .8 Mine 1.6326
CO Max 15.0 Mine 6.3836
NOx Max 2.0 Mine 2.8283

Well, the NOx & CO #s dropped alot.

Original:
HC Max .8 Mine 1.6326
CO Max 15.0 Mine 6.3836
NOx Max 2.0 Mine 2.8283

New:
HC: Max 0.8, Mine .4980
CO: Max 15.0, Mine 9.3472
NOx: May 2.0, Mine 5.3327

How is the engine running? Any misfires? Hgh HC can be misfire related.

Is this a 'Dyno' test??
Ours is at 15mph, then 25mph.

Is it a 2 speed idle test, with no dyno?

If it runs great, then you probably will need a new cat converter. If so, don't get the cheapest one out there. We call them "one pass cats". They don't last.