Why would you pay $80 or more for an HKS or GReddy FCD when you can have:
The Amazingly Cheap $0.27 Fuel Cut Defender
for the Toyota MR2 Turbo
 

While I was at the first SE gathering in Alabama, I got several questions about the zenier diode mod to eliminate fuel cut.  This mod was first made available by Team Toyota Europe as found on the MR2 home page.  This mod involved opening the ECU and soldering a diode onto the circuit board.  I made this mod and found it to work, but it took a major build up of courage to dig into a possible VERY expensive ECU.  Someone on the MR2 mailing list asked if it could be put at the sensor rather than the ECU.  Sure enough,  this mod worked better and is much easier on the stomach to perform.  So, for a grand total of 39 cents, you too can get rid of fuel cut and turn up the boost!

NOTE:  I take no responsibility for any damage done to any part of your vehicle.  This mod worked for me and I was willing to take the risk.  If you are not comfortable mucking around with sensors or electronics, DON'T do this mod.  This mod will completely eliminate fuel-cut as far as I can tell.  The ECU is limited to seeing 4.3V +/- 10% from the boost sensor which equals about 6-7psi on an aftermarket gauge. I have been able to achieve 17psi without hitting fuel-cut.  Be sure to watch your boost levels carefully.  Running more than 16psi is potentially harmful without modifications to the fuel delivery system.
 

Parts
===========
4.3V  400mw (milliwatt) Zenier Diode    - $0.27
Soldering iron
Solder
Electrical tape or some kind of protective wrap
 

Procedure
===========
I didn't disconnect the battery as there is no voltage going to the sensor when the ignition is off ... just make sure the ignition is off while doing this mod.  Find the "Turbo Pressure Sensor" to the right of the intake manifold looking from the rear of the engine bay .. it's next to the diagnosis plug.  The sensor has a 3-wire plug connected to it.

Pressure Sensor

Pull the connector off of the sensor and uncover the wires from the plug ... mine were covered in electrical tape, yours may be different.

FCD Diode

There are 3 wires going to the Turbo Pressure Sensor plug:
  Red   - "Vc" - Voltage
  Brown - "E2" - ECU Ground
  Blue  -  "PIM" - sensor output.

FCD Diode closeup

Don't cut the wires. Strip a section of the insulator from the brown and blue wires; the ground and sensor output.  I made the stripped sections about 1/2" apart in distance from the plug connector; one about 1/2" from the connector and the other 1" from the connector.  This will let the diode lay flat against the wires when you wrap everything up in tape.

Make sure the banded end of the diode is connected to the PIM (blue) wire and that the solder connection is good, wrap the wires tightly with new tape or whatever you prefer, and plug it back in to the sensor.  Crank up the boost slowly and watch the stock gauge; it should stop rising about 2-3 ticks before the + mark.  If it stops rising, you no longer have fuel-cut.  If it goes up to the + mark, double check your connections.

That's all there is to it.  If you have any questions, concerns, or suggestions, please email me at redmr2@home.com.