My friend installed my pfc + commander and didnt cut any of the wires when connecting it? Is it ok to leave it like this, or will there be problems if not cut? Thx -Eric

 

you need to remove the infamous four wires.

1)EGR valve control (Blue/Yellow).
2)EGR switch (Blue/Green).
3)AWS (Brown/Yellow).
4)Split Air Bypass Solenoid (Black/Red).

 

Is it a must, is what my question is? How will it effect my car if not cut. Its really hard to get back there and its all put back in place.

 

you could just pull the pins on the pfc ... then if you want to replace the stock ecm ..just plug it back in

 

I understand the ways of removing the wires etc... my question is how will it effect my car if i dont remove the wires?.......

 

Is it a must, I say no. We know that you can remove solenoids from the harness and the PFC does not care, where as the stock ecu would give an error code. Leaving them on might possibly only affect engine running a little bit.

(1) may or may not permit the exhaust gases to recirculate into the engine as it would with the stock ecu. Mazda did remove the EGR valve around 1994. You could just remove the control hose going to the solenoid or just disconnect the connector on the solenoid.

(2) Only California cars had this. Gave an error code if the EGR was supppose to be working and didn't.

(3) Most people removed the AWS years ago in order to remove the 3000 rpm cold start. If left in, it will either still work as before or not work at all. Can easily remove the connector under the UIM.

(4) Only controls allowing more air to the cat that it normally gets. If not running a cat, not big deal.

As you see none of these are really important functions unless your car is otherwise totally stock and is a CA version.

My PFC pins were cut by the supplier of my PFC so I could not actually do an analysis of the affects of not cutting. Why doesn't someone actually take on this project?

 

The reason behind the wire cutting is the differences in wiring with the JDM harnesses. Those 4 pins have totally different inputs on the JDM harness - if you leave them connected, the PFC might think it's seeing an input it shouldn't.

Read this -

https://www.rx7club.com/power-fc-forum-47/deciphering-jdm-ecu-pinouts-615909/

That thread documents some of the wiring differences. For example the EGR wire on the US harness goes to the TNS (tail, number, stop) relay on a JDM car - it's an input telling the ECU the parking lights are on.

In theory, a US harness could be re-done to be more like the JDM harness - it might help idle control and such, as the JDM cars don't seem to have an ELD (electrical load) sub-computer.

Regardless, it's a good idea to go ahead and modify the harness. Use my method of backing the pins out of the harness, and it will be easily reversible. That will take you all of 10-15 minutes to get to the ECU, back the pins out, and tape them up.

Dale