Hondata

If the ignition is on but the engine not started, what should I see? When KPro's connected, the other variables are reading fine, but MAP is about -28" or so, which seems odd. Voltage on the A-connector pin is ~1.8V, so I know the signal's getting to the ECU.

What does it do when running?

I'm not quite that far along, yet, but almost!

I should add that I'm using a Motorola 2.5 Bar MAP sensor and made sure it's selected.

What it's going into :)

Looking into this further and it's looking like I've got a screwed up ECU. Ever since buying it, A/F only reads 14.7, and now MAP's stuck at -28.9. I rang out the wires and ensured the ground, signal, and reference are present, but it doesn't matter what voltage is applied to the signal input, always stuck at -28.9. Crap.

You haven't even started the engine yet and already your sayign the ECU is bad. Try the ECU on a known good vehicle before coming to this conclusion.

I'd be happy to, but:
1. I do not own, nor know anyone, with an RSX-S, nevermind them letting me plug in a possibly-problematic ECU into their ride.
2. Does MAP read all the time, like coolant temperature, no one will say, but if so, there's something wrong with the ECU, since regardless what voltage (0V, 1.8V, or 5V) is fed into the ECU, it reads a static value.
3. The reason I'm saying the ECU (and not KPro) has problems is because no one has answered #2.

The map sensor does not read until the engine is running.

Try starting the car.

Don't rely on any sensor values in k-manager untill the car is running. Some of them require the car to be started

Okay, thanks. I'm sending it to someone who can check it out on a running car and is very familiar with KPro. This way I at least establish it's a known-working unit - which counts for a lot right now, having changed so much of the electrical system.

The map sensor reading stays at -28.9" until the car is running. Wideband reading sits at 10.70 until the car has been running for at least 30-45 seconds .

Just figured I'd add this so that anyone else researching this will have some answers..

The wideband reading seems to be 10.7 until the sensor warms up - on a cold start (on a cold day), for example, mine does indeed take as much as 30-40sec or so to get a reading. However, on a cold start on a hot day, it's 10-15 - and on a warm start, 5sec max.

Hah, that "someone" is Joe at Locash Racing, who very generously helped me out. Thanks for adding the results of your investigation!