We’ve received a large number of inquiries from people asking whether or not a remap can damage a vehicle’s engine, so we thought we’d answer your questions to help you decide whether or not getting a remap is worthwhile for you.

Understanding the ECU

The electronic control unit (ECU) is your car’s computer. It controls a variety of systems within the engine, including air-fuel ratio, ignition timing, idle speed, variable valve timing and valve control, in real-time through information received by sensors such as the AFR sensor, LAMBDA sensor, throttle sensor and MAP sensor.

The ECU’s original software is designed by the vehicle manufacturer, and pre-defined parameters allow the ECU to interpret information received by sensors as normal or faulty. So for example if there is a fault with the car’s air-fuel ratio, the AFR sensor will communicate this to the ECU, and the ECU will then relay this information you with a check engine light on the instrument cluster.

The problem with the ECU’s original software

The ECU’s original software has slack parameters. These parameters are so because the OEM must design software that takes into account poor fuel quality, a lack of servicing and general neglect. Put simply, the original software is designed for a worst case scenario. This is a problem, because here in the UK we have really good fuel (even the supermarket stuff is decent) and no petrol head neglects their car. So that worst case scenario never comes into play, yet the vehicle is running as if it’s being neglected.

Where remapping comes into play

Remapping is the process of modifying the ECU’s existing code or replacing it with entirely new software, so that it’s optimised for the best case scenario. The way the ECU works, is most cars have two important points on their map – idle and part throttle cruising. All of the points in between are controlled by your car’s ECU in a predetermined pattern. A remap alters this pattern, so the car is no longer being controlled by the OEMs generic software. So depending on the engine being tuned, boost pressure, ignition timing, air-fuel ratio and fuel pressure calibrations (among others) are changed.

Is this safe?

Yes, if the code is altered properly. No two vehicles are the same, and no two engines are the same. In our case, we have remapped thousands of cars, vans, trucks, tractors and a wide range of agricultural machinery and we can categorically say that remapping is a safe modification. We’ve remapped brand new cars fresh from the dealership and owners have reported no issues whatsoever in tens of thousands of miles driving.

You need to have your car tuned by a reputable, competent tuning company that can vouch for their tuning through research. It also helps if they have a long list of glowing reviews and testimonials. All remaps replace the stock calibrations to maximise engine performance by burning the air/fuel mixture as efficiently as possible, but not all are created equal.

It’s also important to bear in mind that with increased power and torque comes greater responsibility – you will be putting more stress on the engine and drivetrain if you drive around at full throttle all of the time. That’s why many people choose to uprate a number of other vehicle components, such as the intercooler and ignition pack, to boost longevity for track days. There’s no need for you to do the same with your daily driver, if you look after your vehicle and drive it ‘normally’.

Got a question about what we’ve written? Have something specific to ask? Leave a comment below, and don’t forget to join the discussion on Facebook.

  • Darren Harris

    I brought my mk1 audi tt about 16 months ago now and it had a lumpy idle when I got it ( ideling between 500 -800 rpms ) and some times cutting out . I have changed every part possible from breather pipes to pcv valve coil packs and spark plugs and all the sensors and it’s still doing it .is it possible that it had a remap in the past that caused this problem as I’m getting to the point of scrapping the car