How to pass CA smog????

[theojo]

to test the egr lift hose going to top of egr from side of black plastic cylinder at idle and suck on it. engine should die. if it doesn't, clogged port in intake . I had that when I first bought mine in 2000. doubt if it is egr gasket. mine had a very slight tear in it and caused computer to pump out excess hydrocarbons at all times.

my 2018 direct fit carb cat from rock auto for $250. must have been a close out. now $1400. although welded carb cat is $250.

got these results. although I'm not in a Nox testing area

[Ian R.]

Thanks Theojo! After doing this it did not affect how the engine ran. It would seem that either the EGR is stuck closed or clogged. With the engine off, and sucking on a tube attached to the port, I can hear the diagram moving inside the EGR. I got the EGR gasket in today. So this weekend I'll attempt to clean the EGR.

[theojo]

Well mine is an 84 yours is an 89. Might be somewhat diff for 89. Tim would know. In this thread I mentioned how I removed tube from exhaust to egr. Then just lift out Egr with tube attached. If you can blow through tube with vacuum on small hose then egr is not blocked
Maybe you’ll see the carbon blocking the hole of the intake under the throttle body. It might be enough just to break it up to allow a path for the air from the exhaust to get into the intake.

But when I removed mine 23 years ago and cleaned it out. There was a lot
of carbon. No problems since

[Ian R.]

Update. I was able to get all the ERG components off. They all are working properly. The EGR Valve diaphragm works. The diagram is able to open the valve and hold the vacuum, allowing air to pass through the exhaust recirculation pipe . The ERG vacuum modulator works. It allows air to pass freely through EGR valve port through ports P and R, blows air through the top filter when ports P and R are plugged, and closes the ports when pressure is applied to the bottom where it connects to the pipe on bottom of the ERG Valve.

So I am kinda scratching my head here. If the ERG system components are working, why would the engine not die or run rough when ERG valve is completely open at idle. Could the opening for the ERG to surge tank be plugged? I gave it a healthy dose of carb cleaner and will let it soak overnight. Maybe I will try to blow air through rubber hose covering the opening where the EGR Valve attaches to see if it clear and unobstructed. I should also check the opening on the exhaust pipe.

On one had I am relieved that all the NLA parts are working. On the other hand I cant figure out why it is not recirculating exhaust .

[theojo]

by surge tank you mean the part of the intake the EGR bolts to? that was my problem. you could get a close fitting hose into that hole and blow to see if air gets through to the intake valves. you might have to turn the engine by hand to make sure one of the valves is open. also could be the port in the exhaust. just turn the engine on and you'll hear it come out of the metal tube going to the EGR

[Ian R.]

I eventually past CA Smog and thought it would nice to share the progression of emissions improvements as parts were repaired/replaced. While not all variables are held constant, I think it provides useful information those that are trying to diagnose emissions problems

Note that the ignition timing was to spec for all tests.

This test shows what CA smog emissions look like with an egr that is not functioning, a failed catalytic converter, old PCV Valve and 02 senors.



Here are the results with the EGR repaired and functioning as the only change from previous test.



Here are the results with a the EGR repaired and functioning, catalytic converter replaced with a CA cat, new PCV, new O2 senors (up/down stream)