So I was thinking about putting a resistor of an undecided resistance in an IAT wire on my 2005 Civic to make the PCM think that it is getting a little cooler air so it advances the ignition timing a little. Is this logical? I am not worried about ping because I use 93 octane fuel. Is this worth trying? I see no way that this can do harm except maybe running a little richer. Should I give this a try?

 

I suspect the behaviors will differ depending on the car. I-vtec operates differently than vtec, and then I suspect obd0 differs from opbd1 which differs from obd2a which then differs from obd2b etc....

I'm pretty sure on obd1 cars, tricking the ecu into thinking the engine is not at operating temp also keeps the fuel maps in open mode so the car will run richer than it should. I am not aware on the timing aspect of the OBD1 ecu.

And I know next to nothing on any of the other OBD's.