I've read the many posts regarding the EGR circuit, and found them very helpful in identifying a bad EGR solenoid. Replaced the solenoid and took it in to get smogged today (So. California). Better readings, actually passed the low speed run, but failed the high speed still, though a lower reading than before the solenoid replacement.
I'm one who hates to take my cars to the shop, and have really loved reading this site.
1. The EGR holds a vacuum, the RPM dips when pushing up on EGR diaphram.
2. No codes (32) anymore after replacing solenoid.
3. I've ohmed the circuits back to the ECM. Took voltage readings at ECM which appear to be in spec, as per something I read somewhere at the time.
4. All vacuum lines are good.

Here are the test numbers BEFORE replacing the solenoid:
TEST RPM CO2 O2 HC CO NO (NO MAX)
15mph 1740 13.67 0.71 75 0.36 1357
25mph 2657 14.00 0.54 37 0.12 1296

Here are the numbers AFTER solenoid replace:
TEST RPM CO2 O2 HC CO NO
15mph 1708 13.50 1.14 91 0.37 0377
25mph 2739 13.80 0.97 36 0.15 1054

(I am not smart enough to make these post in nice corelated columns. Sorry. I think you can draw the lines though, I hope.)

I've seen some great advice for others on this site, and am hoping someone has some wisdom to share. I'm kind of lost at this point. I have a shade tree with no mechanic right now.

Is it possible the intake ports being partially clogged could fail the high speed portion of the test? Yes the RPM dips, but is it possible to be partially clogged, causing this problem? That is the straw I'm grasping right now. Thanks guys.

**Update: 1987, 2.8L, T5, MPFI, Please see attached image w/ test results.

Hi can you tell me more about what failed did it fail for HC NOX Co so on i can not pull up that pic i am at work i live in New Jersey where we have that testing to when was the last time you had a tune up plugs wires cap and rotor if it failing all of them i would think poss you need a new cat converter

It ia failing the NO measurement during the 25mph test. Max measurement is 507, and I have a reading of 1054. The 15mph test passed. Max 549, and measured at 377. I know the alignment of the text is bad, so I attempted to upload a pic. I can open it, but then of course I put it there. ???
Previous to the solenoid replace, the 25mph test, max 507, measured 1269. 15mph test, max 549, masured 1357. Cat is pretty new, as well as the plugs and wires and such.

when you took it thur for testing was the car warmed up or was it cold if it was cold it should of been warm if you have a new cat and egr valve and it is still that high you might have a clouged egr port what kind of cat did you get a 2 way or a 3 way cat 2 ways are always a lot cheper

I took it for a 20 minute drive before testing, and it was tested at 8:45am. Any checks on the EGR circuit look good. I have not checked the intake ports, though the RPM will dip when pushing up the EGr diaphram. Sorry, but what is the difference between 2-way and 3-way cat?

a 2-way cat will only help with hc and co a 3-way cat will help hc co and nox if it was a cheap cat it was probly only a 2-way cat 3-ways are always more also a cloged fuel injector or a vac leak will caus it to be high basicly your car is running lean causing high nox what brand of cat did you get and i hope it was not one of those cheap universal cat from ebay

The engine should die if you open the egr at idle.
Take compressed air & blow through the egr ports, you should hear it very good at the throttle & tail pipe.

Put my Camaro on the back burner since this thing still fails smog after all the work. I looked at the cat tonight just to see what numbers I could find on it. I'm reaching for straws at this point. The only number on there that matched anything on the internet was #93000. Must be a Magnaflow 93000 series cat, which appears to me to not be california compliant, at least that is all I come up with. Don't know if anyone else has seen this.
Any good sources of cats out there, besides the usual parts houses?

After some leg work on this site and the internet, my money lies w/ my cat. At least it is not CA compliant it seems. Guess the smog tech isn't looking too closely. I filed a CAP, so I guess I'll wait to see the results of that, and then go from there. Maybe I can save some money if approved.