Emissions....

Son has a 1990 LE B2200, 2.2L, FI which is (over) due for smog. His MIL light has been lit and we just got around to seeing about fixing it, but ran into some snags.
1. Pulled code and came up with a 3. According to the chart I found on this site, it says it is the "G signal, Dual cylinder injections". Sorry, but that just doesn't mean anything to me. Is there anyone who may be able to clarify that some?

2. In the process, thought I would clean/check the EGR, but I will be damned if I can find the thing!!!! Where the heck is the EGR actually located.

There are several issues with this vehicle and I am sure we will be hitting them one at a time. Right now, I would just like to see it pass CA smog and get him back on the road, so I can have my Ranger back!!!!

Ok, have found that the fuel injected engine doesn't have a EGR valve, so I can quit looking for that.

There is a 2G signall that goes from the distributor to the ECU and someone said that may be the problem. I have to get out and check it, but am wondering what this signal does. It is supposed to go from 0 to 5 volts as you turn the rotor of the distributor. Haven't checked it yet, as son has truck out for the night. Yes, it runs just fine, if only we could get the light to stay out!!

I guess it sounds bad but one thing I did recently on one of my trucks was I disconnected the battery before the test and the light stayed off until I drove home from the test

First, I looked for the reset wires....not to be found. Another site advised us that, the wires were under the hood, passenger side, near the wiper motor. We did find the single green connector that puts the ECU into test mode. That is how we were able to use the MIL light to pull the "3" code.
After reading through the steps in the shop manual, I decided to take a short cut to determine if the "g" signal was working. So I did the following:
1. Measured the wires at the distributor, with the key on and connector disconnected. I got ground, 12v, 5v and 5v. I measured from the ground to the other pins just to ensure the ground wire was actually grounded and it was. Figured this told me that the voltage was making it from the ECU to the distributor, thus the wires must be good.
2. Pulled distributor and measured the second from bottom wire (5v). While turning the distributor, with the key on and connector connected. The voltage went from .2v to 5v. As I turned the rotor the coil would fire and arc from the center point in the cap to the spark plug terimals in the cap. Plenty of spark!!! I was just glad that is where it arced and not anywhere close to my flesh!!!:dj:
So, by doing these checks, I believe I have satisfied the therory that the "g" signal is indeed working.
We also disconnected the neg battery cable (again) to reset the codes. The MIL light went off, until we started the truck up again. Once more, it only took about 10 seconds for it to come on.
I placed my probes in the connector for the O2 sensor, just to see if it would fluctuate. The voltage went from about .9 to .2 volts, back and forth. I am not sure if this is a good voltage reading, but it did jump around.
So, once again, I have run out of ideas as to what could be making the MIL light come on and flash a "3" code. Once again, this is a 1990 B2200 with a 2.2l fuel injected engine.
Will continue to search for the problem, and entertain any logical suggestions.
Thank you, in advance.