One thing we come across regularly at DTUK is the widely held belief that tuning systems are simply a 'resistor in a box', a term that is so common it has its own internet forum acronym of 'RIAB'. This belief stems from a long history of eBay sellers retailing a cheap resistor as a '15bhp power chip' or similar. The 'science' behind it is that a resistor placed across the connection to the Intake Air Temperature (IAT) sensor fools the car in to believing that it is receiving large quantities of cold air and forces the cars ECU to overfuel which in turn gives more power. The obvious downside of this is that the car cannot efficiently burn that fuel and can over time develop serious issues, such as 'borewash', or even complete engine failure, alongside the expected downturn in MPG. As people became more aware of the risks of this modification the eBay sellers began housing these resistors in small boxes and added a simple wiring loom, hence 'resistor in a box'. Some tuning system 'manufacturers' are exacerbating this issue by continuing to retail poor quality systems, in some cases even misrepresenting the contents of their systems. Recently a disgruntled diesel owner contacted us looking for a tuning solution for their vehicle. The customer had previously purchased a system from a rival tuning company. Upon inspecting the system they were forced to question the quality of the kit and wonder whether they have actually got what they had paid for.
Here is a picture used by the 'reputable' tuning company to show what the customer would receive for his VAG 1.9 PD engine

Here is what the customer found when they disassembled the system

As a direct comparison, here is the image used on the DTUK website to show our tuning system for the VAG 1.9 PD engine

and here is the system we are shipping out to that very customer

Unfortunately, this customer has found the hard way, that the old adage of 'buy cheap, buy twice' certainly applies to the world of diesel tuning