Exhaust Gas Recirculation and EGR system removal or repair
Modern vehicles are massively advanced compared with their counterparts of even just a few years ago, and this is especially notable in areas such as economy, performance and exhaust emissions. Many of these advances are down to the application of technology. However, as with many other things, much as it can vastly improve matters technology can also cause problems, especially when vehicles become older and reach higher mileages. EGR is short for Exhaust Gas Recirculation, and is a process whereby a small amount of the exhaust from an engine is returned to the combustion chambers, with the effect of reducing the 'burn' temperature and thereby lowering the overall proportion of carbon monoxide emitted. This is because the production of carbon monoxides is (primarily) directly related to the temperature at which the fuel and air mixture burns. The system was devised and first implemented in the USA and was fitted to many cars before the wide-scale introduction of catalytic converters. EGR systems today remain a common fitment on both diesel and petrol-engined vehicles.
Notwithstanding the potential benefits, set up to run correctly, modern engine management computers ensure that the vast majority of vehicles exhibit little difference in overall exhaust emissions with or without an EGR system fitted. This is especially the case now in Europe, as modern fuels must meet applicable standards and contain far fewer additives and contaminants than was the case in the past. EGR systems are also known to adversely effect economy and performance, and research suggests that this can easily amount to as much as a 5% increase in fuel consumption, with ironically a corresponding increase in overall exhaust emissions. The long-term reliability of the systems can further be a serious issue, especially with older and higher mileage vehicles. The system contains a number of valves and moving parts and needs to be fitted to the exhaust at its closest point to the engine itself. As a result, the components are subjected to vibration and extreme variations in temperature. In the event of failure, complete replacement was initially considered to be the only solution, but the costs can be extremely high. Failed or damaged EGR systems must be attended to, however, as they can cause significant loss of performance and increased fuel consumption, and can also lead to serious engine damage in the longer term.
As a consequence, EGR removal has become acknowledged as the obvious solution and is a relatively simple and straightforward job, involving physically or electronically blocking out the system and preventing it from operating. However, simply removing the relevant parts or altering the software alone is insufficient. In virtually all modern vehicles fitted with such systems, EGR removal must be carried out to include not only physical removal or disconnection, but also properly and fully updating the vehicle's electronic control unit with a revised engine 'map'. Done correctly, this process will enhance both fuel economy and performance and improve general running, whilst still allowing the relevant vehicle to easily meet MOT standards for exhaust emissions.
BEWARE! We have been advised that a number of companies that offer EGR removal are just turning off the EGR fault code system and deleting the code that runs the system. This means that the fault light for EGR problems is no longer illuminated, but the software is only partly changed. This can potentially result in serious engine damage. Some other companies reset the software to prevent the system from operating, but no not correctly and fully reprogram the engine management system, resulting in poor running and fuel consumption, and the likelihood of the vehicle not meeting MOT standards for emissions.
At MK T and B Centre we have the equipment, training and necessary software and vehicle 'maps' to ensure that EGR removal is carried out correctly. Please contact us for a quotation or for further information.
