Apparatus and method for adjusting the performance of an internal combustion engine

1. An apparatus for modifying the performance of an internal combustion engine of a motor vehicle including fuel injectors, an oxygen sensor for sensing the amount of oxygen in the exhaust gas produced by the internal combustion engine, and a preprogrammed electronic control unit for receiving a voltage signal from the oxygen sensor, and in response thereto producing fuel injector control signals controlling the operation of the fuel injectors, the apparatus comprising:

a voltage modifying means for proportionally modifying a reference voltage as a function of the voltage signal of the oxygen sensor to modify the fuel injector control signals produced by the electronic control unit without modifying the programming of the electronic control unit; and

said voltage modifying means being interposable between the oxygen sensor and the electronic control unit.

2. The apparatus of claim 1 , wherein said voltage modifying means modifies said reference voltage to cause the electronic control unit to produce fuel injector control signals that provide a richer fuel mixture to the internal combustion engine than what would be provided in the absence of said voltage modifying means.

3. The apparatus of claim 1 , wherein said voltage modifying means passes through the voltage signal of the oxygen sensor to the electronic control unit without modification of the voltage signal.

4. The apparatus of claim 1 , wherein said voltage modifying means includes a resistor circuit which passes through the voltage signal of the oxygen sensor to the electronic control unit without modification to the voltage signal, and divides the voltage signal of the oxygen sensor based upon the resistance values of a resistor pair and adds the divided voltage to said reference voltage.

5. The apparatus of claim 1 , wherein said voltage modifying means increases said reference voltage.

6. The apparatus of claim 1 , wherein said voltage modifying means includes a resistor circuit.

7. A method for adjusting the performance of an internal combustion engine of a motor vehicle including fuel injectors, an oxygen sensor for sensing the amount of oxygen in the exhaust gas produced by the internal combustion engine, and a preprogrammed electronic control unit for receiving a voltage signal from the oxygen sensor, and in response thereto producing fuel injector control signals controlling the operation of the fuel injectors, the method comprising the steps of:

interposing a voltage modifying means between the oxygen sensor and the preprogrammed electronic control unit;

passing voltage signals from the oxygen sensor to the preprogrammed electronic control unit without modification to the voltage signals;

proportionally modifying a reference voltage with said voltage modifying means as a function of the passed voltage signals from the oxygen sensor to produce a modified reference voltage;

generating modified fuel injector control signals as a function of said modified reference voltage without changing the programming of the preprogrammed electronic control unit; and

employing said modified fuel injector control signals to cause the fuel injectors to provide a richer fuel mixture to the internal combustion engine than would be provided in the absence of the step of modifying the reference voltage.

8. An apparatus for modifying the performance of an internal combustion engine of a motor vehicle including fuel injectors, an exhaust gas sensor for sensing an amount of a constituent of the exhaust gas produced by the internal combustion engine, and a preprogrammed electronic control unit for receiving a voltage signal from the exhaust gas sensor, and in response thereto producing fuel injector control signals controlling the operation of the fuel injectors, the apparatus comprising:

a voltage modifying means for proportionally modifying a reference voltage as a function of the voltage signal of the exhaust gas sensor to modify the fuel injector control signals produced by the electronic control unit without modifying the programming of the electronic control unit; and

said voltage modifying means being interposable between the exhaust gas sensor and the electronic control unit.

9. The apparatus of claim 8 , wherein said exhaust gas sensor is an oxygen sensor for sensing the amount of oxygen in the exhaust gas.

10. The apparatus of claim 8 , wherein said voltage modifying means modifies said reference voltage to cause the electronic control unit to produce fuel injector control signals that provide a richer fuel mixture to the internal combustion engine than what would be provided in the absence of said voltage modifying means.

11. The apparatus of claim 8 , wherein said voltage modifying means passes through the voltage signal of the exhaust gas sensor to the electronic control unit without modification of the voltage signal.

12. The apparatus of claim 1 , wherein said voltage modifying means includes a resistor circuit which passes through the voltage signal of the exhaust gas sensor to the electronic control unit without modification to the voltage signal, and divides the voltage signal of the exhaust gas sensor based upon the resistance values of a resistor pair and adds the divided voltage to said reference voltage.

13. The apparatus of claim 8 , wherein said voltage modifying means increases said reference voltage.

14. The apparatus of claim 8 , wherein said voltage modifying means includes a resistor circuit.