My car, 1992 Honda Accord Wagon, passed the emissions tests but failed on the function part. Tech said that the EGR valve was functioning correctly, but that there was no vacuum being applied to it. I took the control Box apart and checked the parts for blockages, I took the solenoid and manually energized it via the battery, it cycled fine and I could get flow through it when it was on. The only thing I can think of is that the computer is not sending the signal to turn it on. Anybody out there have the knowledge of how that all works and what I should look for next?

 

How did he test it? Certain EGR valves will only operate if the engine is on. You cannot always just test the diaphragm with the engine off. Is this the same shop you always take your car to be smogged?
As for vacuum it should only be activated around cruise rpm. If he tested it at idle you would not have vacuum.
I'm thinking the tech goofed.
Without EGR the car would probably not pass NOx or barely pass the NOx with a new catalyst.

Post the five gas measurements.

 

The smog tech probably spent too much time performing emissions tests by inhailing the tailpipe gases. A taste-test is not part of the exam.

EGR relies on RPM and ECT on your vehicle. If the ECT is at operating temp and you GENTLY and SLOWLY tip into the throttle in park, from idle, you should see vacuum to the EGR valve.

 

I wasn't able to actually observe the tech during the test, but the results page states: fail, egr functional. The tech wrote the following comments "EGR Functional, valve working, apply side does not"

The emissions test results:
Idle test: PASS
RPM = 975
%CO2 meas = 14.6
%O2 meas = 0.5
HC (PPM)
Max = 120, Ave = 29, Meas = 74
CO (%)
Max = 1.00, Ave = .10, Meas = 0.49

2500 RPM test: PASS
RPM = 2431
%CO2 meas = 14.5
%O2 meas = 0.6
HC (PPM)
Max = 140, Ave = 20, Meas = 47
CO (%)
Max = 1.00, Ave = .10, Meas = 0.71

It has the standard 2.2 L w/ 247,897 miles on it

 

I guess I should add also that I have had the car for about 2 years now and that it has always had a few quirks. One of the worst is that when it idles under load, i.e., in drive, stopped at a light, it is very rough. If I put it in neutral or park it smooths right out though.

It also will on occasion not start right after you shut it off, acts like it isn't getting any fuel, then suddenly after a few attempts/minutes it will start right up. Occasionally the drive indicator on the dash will start flashing and the car wont shift into 1st, that usually will resolve itself if I let her warm up a bit, then turn it off and then restart it. But hey, the car is old and has a lot of miles on it, lol.

 

^^ My car does that that too, but mine is MT. Say I stall, it wont turn right back on. I would have to remove the key and start over again, not just turn the key.

 

I only see four gasses. CA tests for five. Wheres the NOx readout? That is what EGR reduces NOx.

 

Ill have to look over the report again, but i believe there was no actually readout of NOx. It just says something to the effect that the functional tests are to ensure NOx is within parameters. I wil scan the whole page and post it up for you in a bit

 

My Son-in-law and his brother own a custom 4x4 shop, but they also have a nice Snap-on scanner with all the modules. I am going to borrow it and see what kind of information I can glean of of it. I used it on a Buick Le Sabre once and it allowed me to cycle all kinds emissions devices and parameters.

 

There was no NOx readout because your car was tested as two speed idle test. One at 2500rpm and idle. EGR does not function w/out load. So that's why the smog tech needed to do a EGR functional test. He most likely used an EGR Electrical tester. He opened the valve with the tester and most likely did not open(EGR diaphragm torn) or it did open but did no effect on the engine, meaning the EGR ports where really clogged. You should check EGR function first before you replace the EGR.

 

I read this and I knew in CA there were a few areas where you did not have biannual smog testing, but I was surprised there are FOUR different area requirements. I was under the impression you either had the full test or none at all.

Enchanced(full dynamometer test)
Partial Enhanced (?)
Basic (idle/2500 testing)
Change of owner ship (testing only when change of ownership)

http://www.bar.ca.gov/80_BARResource...2-09%20V-2.pdf