I recently bought one of those cheap-o Resistor Chips that says: This simple, yet effective modification that will allow you to boost the power output of your vehicle's engine, without sacrificing reliability or comfort. It consists of a small electronic device that will be inserted between one of your car's sensor and the ECU. This is also know as a 'piggy back' device as it is external to the main processing unit (the ECU). You will feel the gain instantly, no fooling around or expensive tuning necessary.

This unit will work with all vehicles equipped with electronic fuel injection. 99% of cars manufactures after 1988 are equipped with electronic fuel injection. You probably heard of ECU chips, these chips can be found to be quite effective, but also pricey as you not only need the chip, but also a socketing kit. You then need to do some soldering on your computer board which can damage it and cause it to malfunction. On the other hand, this 'piggy back' electronic device will alter the fuel and timing curves in a very similar way as the EPROM chip would, but without even opening the ECU. How can it do that? By fooling your computer and letting it think that you are sucking air at a different temperature. Your computer will respond with increased power!

I know its a really cheap way to get minimal gains in performance but my cash flow for this summer is VERY limited (new house, dog, and gf within the same 2 months ) and I figured for 8 bucks wtf. As soon as I installed the resistor chip my check engine light came on. Is this normal when using one of these or should I be alarmed???