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ECU Remapping and the Inadequate Preparation

by Andy Published on Thursday, April 30th, 2015

There are now a multitude of companies that will remap the ECU on your vehicle. In most cases, this entails plugging a computer into the diagnostics port on your vehicle that directly communicates with the ECU. A technician reads the existing file on the ECU and overrides it with a new file. The new file has on it adjusted parameters which alter a number of characteristics on the engine. These include the amount of turbo boost pressure (if applicable), the fueling and ignition timing (if on a gasoline vehicle), and other such parameters.

What can happen on a diesel engine after remapping is that the amount of smoke coming out the exhaust increases, particularly on heavy acceleration. Where you once had a small amount of smoke from your exhaust, you now have a problem with a heavy amount of smoke. Any underlying running problems can be exacerbated with an engine remap. One of the things that surprises me tremendously is that many companies do not carry out a health check. Lots of remap servicers are mobile; they do not have the necessary tools, equipment, or expertise to precheck the vehicle. None of them, as far as I have researched, ensure that the fuel system is running correctly and that there isn’t an excess of carbon buildup.

If you are pushing the engine by asking it to work harder and produce more power, it is essential that you ensure that you have the best platform from which to remap and gain that additional performance. To guarantee this, the first thing we advise is to carry out a health check. Make sure there are no error codes. Then combine the remap with a professional fuel system cleaner and carbon remover. It is essential that the fuel system is running efficiently before you remap your vehicle. On a petrol engine, it is essential that the ignition components, the ignition system, and the fuel system are performing optimally in order to maximize the benefits to be gained from a remap.

Wherever you go to have your vehicle remapped or chipped, make sure the service includes the necessary checks. Also make sure you use a high-quality fuel system cleaner, particularly if your exhaust has any excess smoke. If you have excess smoke, I strongly advise that you get the issue resolved or checked before performing a remap.

2 thoughts on “ECU Remapping and the Inadequate Preparation”

Bill Martin says:

May 2, 2015 at 1:04 pm

My 2002 2.2 litre petrol Vauxhall Omega is a cherished vehicle in superb condition and runs very well. Care for this car included fuel system cleaning with AR6400 and this is supplemented with AR6200 for subsequent fueling. From the MPG point of view I am convinced the car would perform even more frugally with the ECU re-mapped to allow for slightly lower engine revolutions in all gears. I am convinced I can get better than 40mpg distance mileage if this were undertaken. I base this observation on the lower engine revolutions of my other car (Mercedes C180 petrol auto) with which I can attain 50mpg on distance motoring. If I am already getting what many would judge as good MPGs with the Omega, would you consider ECU re-mapping worth doing?

Reply
1. Andy Archer says:
  
  May 6, 2015 at 10:02 am
  
  Hi Bill, I have updated the article to include info on how MPG is increased through engine maps. From my experience the MPG gains on that engine would be too low to justify the cost of a remap.
  
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