edit: 1996 accord with the 2.2 non-vtec 5-speed 178k

I've run through the entire gambit with this code as follows:
original code 3 months ago; cleaned up the egr ports on the intake manifold (every one of them were clogged) & that fixed the problem.

3 months later it's back...

I double checked my work on the ports & all was clean, I ran the car at idle while applying all of 6" of vacuum to the egr valve & it stalled. I tested the egr vacuum regulator thing along with the egr vacuum solenoid & all tested ok...I then pulled out the ECU & tested all the corresponding voltage readings there with nothing showing bad & replaced all vacuum lines...yet the 'check engine light' with that code keeps popping up.

so, I'm left with one question before I swap out the ECU; could anything else trigger that code? like a bad O2 sensor or something?

thanks in advance,
-hecubus

 

When the ECU commands the EGR to turn on, the ECU then looks for the change of the EGR lift sensor, and also a change of the MAP sensor.
The MAP sensor is the 'snitch' of the operation.
You seem to have done good solid diagnostic, procedure.
I'll see if I can get you some more info.
This is a strange problem, no doubt.

 

update:
I had a few moments this afternoon before it got dark & checked the voltage going to the MAP sensor, here's what I found:

one lead had a constant 4.96 volts to ground & center wire. I'm guessing this is the sensor's power supply

(I'm assuming the center is a ground)

other lead had 3.5 volts with the car in the 'on' position but the engine not running to ground & the center wire.
same lead had .89 volts with the engine running @ idle & would jump up to ~2.5+ volts if I revved up the car.

...are these normal readings?