It's only a matter of time before someone comes on asking about those eBay tuning chips that can "Add 20+ BHP", so I thought id write an article on it now to save the time later.
![]()
So What Do They Do?
Well, one thing they don't do is either chip or tune your engine. Only a proper ECU chip, tuned to your specific engine can do that, something like Hondata.
What they are is a resistor. A simple electronic resistor like below, which can be bought from somewhere like Maplin for around £0.50.
![]()
This resistor slows down (resists) the signals being sent from your engine to your ECU, in order to give it false information. This false information includes the temperature of the air going past the air temperature sensor. It tells the ECU that this air is colder than it really is. As I explain here, the colder the air the denser it is, and so theoretically the more oxygen it holds. Oxygen makes the mixture of petrol and air burn better, so cold air is good.
So, with the ECU thinking that the air is colder and with more oxygen, it happily provides more petrol to the engine. More petrol than is actually needed by your engine. You may notice a slight power improvement, although often the opposite is true.
So Why Is This Bad?
Well here are just a few of the problems that can be caused by the wrong amount of petrol being fed into your engine:
- Detonation: Early combustion of fuel in the cylinder before the spark plug has had a chance to fire.
- Lumpy Idle: Your engine's idle speed surging up and down.
- Bore Wash: Excessive petrol gets into the cylinders and stops the piston rings from sealing.
- High Emissions: To much exhaust gases which you will fail your MOT for.
- Low Mileage: Your petrol tank will not take you as far.
Convinced Yet?
Well, you should be. eBay "tuning chips" cause no end of trouble, and are to be steered well clear of.
Hope this article helped.
So What Do They Do?
Well, one thing they don't do is either chip or tune your engine. Only a proper ECU chip, tuned to your specific engine can do that, something like Hondata.
What they are is a resistor. A simple electronic resistor like below, which can be bought from somewhere like Maplin for around £0.50.
This resistor slows down (resists) the signals being sent from your engine to your ECU, in order to give it false information. This false information includes the temperature of the air going past the air temperature sensor. It tells the ECU that this air is colder than it really is. As I explain here, the colder the air the denser it is, and so theoretically the more oxygen it holds. Oxygen makes the mixture of petrol and air burn better, so cold air is good.
So, with the ECU thinking that the air is colder and with more oxygen, it happily provides more petrol to the engine. More petrol than is actually needed by your engine. You may notice a slight power improvement, although often the opposite is true.
So Why Is This Bad?
Well here are just a few of the problems that can be caused by the wrong amount of petrol being fed into your engine:
- Detonation: Early combustion of fuel in the cylinder before the spark plug has had a chance to fire.
- Lumpy Idle: Your engine's idle speed surging up and down.
- Bore Wash: Excessive petrol gets into the cylinders and stops the piston rings from sealing.
- High Emissions: To much exhaust gases which you will fail your MOT for.
- Low Mileage: Your petrol tank will not take you as far.
Convinced Yet?
Well, you should be. eBay "tuning chips" cause no end of trouble, and are to be steered well clear of.
Hope this article helped.
