Well I went to get the car e-checked today but it flunked.

Here are the things they checked.

HC 11.0 PPM 152 PASS
CO 0.00 % 0.97 PASS
NO 2317.7 PPM 1082 Fail
CO2 14.12 % N/A

Here are some things that I think were wrong for the test.

Idle was too high 1400 rpms.
Initial timing set at 18+ degrees advanced


Items that are missing from the car are:

EGR valve.
The whole AIR system. (Smog pump stuff)

I wonder if the NO will come down enough after setting the timing back, idling down to about 750 rpms. I wonder if re-installing the EGR will bring it down enough. It will take some doing to put all the smog pump and stuff back on.

 

Typically, high NOx readings are due to high combustion chamber temperatures. The EGR system introduces exhaust gas into the intake stream which cools and lowers combustion chamber temperatures.

Get the EGR system working again and you should be fine.

BTW, you're missing the AIR equipment; doesn't your state's emission testing have some kind of equipment requirement in addition to a "sniffer" test?

 

Definitly failed due to No EGR. I am having a similar problem... Except I have my EGR system on there...Its just not working!!!

 

I will have to reinstall the EGR valve and reset the timing to stock specs and bring the idle down too. I think an oil change might help things as well. All of the ignition is new.

Let me ask you guys something. Before the EGR valves came out in 1973 were combustion temps real high? If they were, wasn't that detrimental to those engines. I have always thought that unburnt exhaust gases were reintroduced into the combustion process and diluted the intake charge.

Is the sole purpose of the EGR valve to control combustion temps?


Am I failing to understand how the basic EGR systems works?

The AIR system probably is required but OHIO's E-check stations do not do a visual on the car except to check and see if it has Catalytic converter installed.

 

I passed an Ohio E-Check without the use of EGR or AIR. High combustion temps are generally a result of a lean mixture although you would generally see HC come up to some lean miss.

If this was your first test, I would drop ignition timing back to stock, put regular 87 octane in and retest.

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