Rev limiter at 3200 on CEL, suspect IAC valve

Hi All
I just bought a month ago an integra 91 LS 3 doors.
I had an Intermittent CEL and when the light would come on, the rev
limiter would kick in and limit at 3200 rpm and the Idle would stick at
around 1700.
This would last for about 10-15 min and then return to normal and I
would get back to the full RPM range but a rough coughing idle at 700.
I finally learned how to read the CEL code from the ECU by jumping the
diagnostic connector under the passenger dashboard.
I got a 12 and a 14.
12 (EGR) (Exhaust Gaz Re circulation)
14 (IAC) (Injection Air Control)
I read somewhere that the code 12 can be random since there is NO EGR
valve on the 1991 Integra.
So I focussed on my IAC Valve. I first removed it to clean it
thoroughly with Berryman B12 Chemtool Carburetor Cleaner.
I also sprayed generously inside the intake manifold.
After re-installing it, It seemed to be better for the first few hours
and then the CEL came back and never left.
My intermittent problem was now permanent.
I then went to the scrap yard and scavenged an IAC valve from a dead
Integra.
Once I installed the "new" valve, I was back to square one,
intermittent CEL, rev limit and rough idle.
The one thing peculiar is that I never was able to re-read the codes. I
tried to pull out all the fuses from the relay box, and even to
disconnect the neg. pole of the battery for 10 minutes at the time.
Nothing. The red LED stays on and does not blink anymore, with or
without the jumper.
Needless to say that I've already changed the oil, spark plugs, cables,
cap and rotor.
I read somewhere that there was a special procedure to extract the ECU
codes related to prgm-fi problems.
I am running out of inspiration, any ideas someone ?