Can the factory ecu be 'tricked' to run richer?
 

Is there some way it can be 'tricked' into running richer in the mid range and top end? Or is there any other way of getting more fuel into the engine with the factory ecu? I belive the fuel pump resistor can be by-passed but I don't know if that will help with top end AFRs.

So many FD's have the usual intake and exhaust mods and tend to run lean, it would be handy if there was a quick 'fix' to make the AFRs safe.

That is what "piggy-back" ECUs do: fake inputs to the factory box. It's a crude way of controlling the engine, compared to a stand-alone system.
The fuel pump resistor will only affect pressure before the regulator, not at the injectors.

The stock ECU is fine at stock boost levels with bolt-on mods.

While you could use an aftermarket fuel pump with a Rising Rate Fuel Pressure Regulator to get more fuel, you'll still be dealing with fuel cut on the stock ECU. By the time you add in a fuel cut defenser, you are already at the price of an aftermarket ECU.

Does unplugging the oxy sensor send the ecu rich? Or maybe putting a resistor in the wire?

You can buy a used "chipped" stock ecu for around $300 in the parts section. Pettit and M2 upgraded many stock ecus to provide more fuel at higher boost levels.

i can sell you my m2 if you want... proven to work!

Not under boost.

Wrong, wrong, and wrong again. If everything on the car is working properly, you can run all of the bolt-ons at 10 psi on the stock ecu and still be comfortably rich. There is no reason to do what you are proposing whatsoever. If you want to run over 10 psi, you need a chipped ecu or standalone ecu (like the Power FC). There are no good ways around this.

What he dosent know is that the ecu only runs off the oxegen sensor under 3000 rpm. At that point it switchs over to a pre set fuel map. That does two things causes the wierd 3000 rpm hesitation on some cars and limits the amount of boost you can run, because the fuel will never change.

don't go the 'cheap' way. save the money and buy a good ECU like the power FC

saving a few hundred bucks now is not worth the risk of blowing your engine.