The 3 holes on the digital EGR valve

[rtt1969]

On my 1995 firebird 3.4 eng. I have a digital egr valve.

It has 3 holes on the underside. The trouble code says #1 solenoid failure.

I don't know which of the 3 holes is #1

There is a small hole, a little bit bigger hole and a bigger hole.

Does anyone know if the smallest hole is #1

or would the bigger hole be #1

[Ridenour]

I would guess that the biggest hole would be solenoid #1. - Are you just going to clean it with carb cleaner, or what?

[rtt1969]

The check engine light only goes on if I am on the freeway over 55 mph and then slow down. So at 55 mph no light, when slowing down to 54 the light comes on.

Since I think NOx is higher at freeway speed, it makes sense that the big hole would open, and if it failed and showed #1, I guess #1 would be the big hole.

It's just that I am failing the smog check at 25 mph, but the light doesn't come on at that speed, only at 54 mph if I slow down to 54 mph.

I'm trying to figure out what hole opens at 25 mph.

The EGR works, I tested it, the connector has a good connection, I checked for voltage and ground. So I can't figure out why I would get a solenoid failure, if voltage and ground are going to the solenoids and the EGR valve is new, no carbon blocking the holes from opening.

Unless when the #1 is supposed to open, a sensor is shutting off the ground to that solenoid, but what sensor would tell the EGR to turn on and off. Both Oxygen sensors are new.

[jason-1995fbody]

is it a new egr or one you cleaned

[rtt1969]

I first had this trouble with an old EGR a day after I bought the car, but the dealer did the smog check and I was good for 2 years, so it was no big deal and it was under the old smog rules, otherwise it would have failed for the dealer.

I thought it was a bad EGR valve when it said code 75 so I bought a new EGR valve for $200.00 and still had the same problem, code 75.

Now it's time for a smog check under the new california rules and it failed because of that code 75. So I tried everything I could think of to make it pass, but I wound up taking it to a mechanic and it

Finally passed. They said the EGR ports were clogged. I don't know how they could be clogged, since I tested the EGR and all 3 solenoids opened. But they cleaned it out and it passed the smog check. Cost me $340.00 to have that done, plus the smog check.

Here's what my #'s were, incase anyone is interested.

This is what they allowed 15mph HC 84 CO .49 NO 692
25mph HC 49 CO .46 NO 711

First test 15mph HC 6 CO .06 NO 1181 fail
25mph HC 5 CO .05 NO 1400 fail


Then I put in new spark plugs and wires.

15mph HC 1 CO .01 NO 1467 fail
25mph HC 0 CO .01 NO 1444 fail

Then I cleaned out the EGR passage inside the upper intake manifold

15mph HC 13 CO .07 NO 686 pass
25mph HC 1 CO .01 NO 1163 fail

Then I tried some stuff I bought on the internet, some blue sky stuff and also used octane booster.

15mph HC 7 CO .06 NO 659 pass
25mph HC 4 CO .05 NO 1152 fail

After the mechanic did the EGR port cleaning

15mph HC 3 CO .02 NO 429 PASS
25mph HC 0 CO .01 NO 549 PASS

Total cost to get my car to pass this stupid smog check, $640.00