First of all, thanks to Terry for splitting up the old thread so that this could stand alone. This topic deserves some good discussion. Fortunately I see that there are already some smart people involved in this thread - so to keep the ball rolling...

Question for Paul - Are you suggesting keeping the ECU in open loop forever? Pursuing this route concerns me a little, because isn't this in itself grounds to flunk sm*g? (Or is the ECU not checked for being in closed loop during the diagnostic dyno run?)

Question for Terry - Can you possibly give more details on what you saw when the injector code was thrown? What year was the ECU that you looked at? What conditions was the car under when the code popped up?

Comment for Justin - Actually, that's kind of what I was expecting from a 95 ECU. We should be specific in this thread about separating the OBD-1 ECU from all the other years that had OBD-2.

FYI, I have a little birdie that gave me some info from a Satan insider. It confirms what Terry is saying, that the stock ECU is sending a different pulsewidth and expecting the O2 sensor to respond in a certain way. Unfortunately, this person wasn't allowed to divulge too much info.

So what I'm looking for is some empirical data showing us what exactly is happening when the code is being thrown. Is this a diagnostic test that the ECU does at certain times (analogous to the EGR test the computer performs at *specific* times, with expected *specific* sensor signals.) For example, the EGR test is performed during cruise, causing hot exhaust to recycle into the engine, displacing oxygen, thereby causing the O2 sensor to respond in a certain pattern. Now, does the injector issue arrive after a certain diagnostic test is performed, or is it monitoring for this event all the time, or is it only under certain driving conditions (like decelerating or a decreasing load where the pulse width is progressively becoming smaller.) Terry you may be the only one with enough experience on this to answer. I'm talking with a lead engineer from a major player in the aftermarket world, and any insights would be of great value.

2gnt: '99 RS-T, killed by a toyota, pending rebuild...
Daily: Volt
Daily #2: '99 EVG ebike- STOLEN by PEDRO