I failed emission today due too to high CO%. I failed at 15 MPH and passed at 25MPH.
Here are the results:
<table border=1>
<tr><td> </td><th colspan=3>15 mph</th><th colspan=3>25 mph</th></tr>
<tr><td> </td><td>limit</td><td>reading</td><td>result</td><td>limit</td><td>reading</td><td>result</td></tr>
<tr><th>HC ppm</th><td>111</td><td>42</td><td>PASS</td><td>108</td><td>65</td><td>PASS</td></tr>
<tr><th>CO%</th><td>0.62</td><td>1.01</td><td>FAIL</td><td>0.66</td><td>0.05</td><td>PASS</td></tr>
<tr><th>NO ppm</th><td>848</td><td>561</td><td>PASS</td><td>773</td><td>680</td><td>PASS</td></tr>
<tr><td> </td><td>RPM</td><td>895</td><td>VALID</td><td>RPM</td><td>895</td><td>VALID</td></tr>
<tr><td> </td><td>Dilution</td><td>14.6</td><td>VALID</td><td>Dilution</td><td>14.0</td><td>VALID</td></tr>
</table>

Here is the emission equipment I ran on my car during the test:
- Catco high flow cat (no air line)
- NO ERG (ZZ4 / Corvette heads)
- Smog pump
- Smog legal headers with lines connected.
- Charcoal canister

Anyone have any suggestions on how to lower the CO% output? What is the cause of high CO% levels? I have the ability to burn my own PROMs so if it can be fixed with lowering timing or something let me know.

 

There's the answer.

The cat cannot turn CO into CO2 without oxygen.

Your ECM instructs the AIR mgmt valve to send the air to the headers when the engine is cold, and to the cat when the temp reaches where it goes to closed loop. Since you have no AIR line to the cat, you essentially have forced the system to shut down when it enters closed loop.

Cause the AIR system to send the fresh air to the headers 100% of the time.

 

RB83L69,
I hooked one header per port on the smog solenoid so the emission guy wouldn’t notice a port with nothing on it and say something about it. Do you think if I hook both headers to the cat output port on the smog solenoid it would take care of the problem? Any reason I would pass at 25 and fail at 15?

 

ttt

 

How thoroughly do they "visual" it?

Also, does the cat itself have the AIR line hookup?

 

Thanks for the replys,
Well I don’t have an EGR valve and the guy didn’t see that but he did take a look at the whole smog pump setup. I also do not have the air line hooked to the cat as stated above (removed the tube when I did the engine swap). Each outlet on the smog solenoid goes to a separate header to give it the appearance everything is hooked up.

Would a rubber hose melt if I try to run it to the cat because it would be a huge PITA to put in the stock metal air line?

 

If the cat itself has the air line, go to the hardware store, and get a compression fitting for ½" tubing, which is the size on the cat; and a short gas line for a water heater or something, which is stainless; and a hose nipple for ¾" hose. And just hook it up and be done with it. Probably make it just fine like that.

FYI, my car made it through California "enhanced" emissions inspection, with the full **** probe and cavity search procedure, with gas line on it for that.

 

thanks!
I have a few more questions. What is a compression fitting and is 3/4 the size of the smog valve fitting or what is the 3/4 fitting for?

 

heater hose