performance chip!!

[Loren]

There is no "circuit", it's just a resistor in a fancy box. It is installed inline with the intake air temp sensor and causes the ECU to read the temperature as lower than actual. Since cooler air is more dense, this makes the ECU "see" that more air has gone into the cylinder and it injects more fuel. A slightly richer mixture can give more power under some circumstances. But, this only happens at full-throttle or during warm-up when the ECU is not in closed-loop operation. In closed loop, O2 sensor feedback will correct the error induced by the faulty temp data.

So, it "might" give you slightly more power when you get on it, but there's no way it's going to improve fuel economy.

That's all there is to it.