EGR DELETE / EGR BYPASS
The EGR valve (Exhaust Gas Recirculation) is an emission control device designed to reduce NOx emissions to help towards the ever more stringent Euro Emission Regulations developed partially as an anti-lag feature in Group B Rally cars, random fact!

EGR Delete and EGR bypass software is designed to remove the functionality of the EGR valve to ensure it removes the running issues associated with these devices or changes the performance of the car in two ways, deleted due to the way it works on diesel cars it can reduce burnt fuel in the way of soot being placed back into combustion reducing performance where fresh fuel and air would be more desirable, the downside will be slightly reduced throttle response as the air flow from the EGR will help keep the boost pressure available with the turbo still spooled and more responsive.

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HOW DO EGR VALVES WORK?
The EGR Valve creates a loop back from the exhaust manifold to the intake manifold to recirculate burnt gases. The EGR valve has a solenoid which controls the valve which in turn is controlled by the ECU. The ECU operates the solenoid by using a duty request cycle in order to open the valve and recirculate the burnt gases.

The Manifold Absolute Pressure sensor is then used to record the amount of additional gas which subsequently feeds back to the ECU as a control measure.
 

 

EGR VALVE PROBLEMS
As the EGR valve is constantly working with burnt exhaust gases they naturally have high soot content. This soot in the gases causes a build-up of carbon deposits around the valve operation area which in turn causes the valve to tend to stick in various positions. For full engine performance the EGR valve is closed which creates a closed loop environment for the turbo system which allows it to pressurise. A problematic EGR can create an open loop environment for the turbo as it provides a feedback straight to the intake manifold and as a result can cause boost issues along with huge reductions in power and fuel economy.

 

 

BENEFITS OF EGR REMOVAL - EGR DELETE
Restored Engine Power where the EGR is failing
Restored MPG
Cleaner emissions as faulty EGR’s create much higher soot deposits
Can prevent DPF failure as the soot is caught in the DPF trap
Can prevent EGR replacement which can cost hundreds of pounds.
Having your EGR deleted in software can save you money in repairs and in fuel costs. We are at the forefront of EGR Removal and EGR Bypass software and can correctly remove the functionality from the software of most ECU types. Some companies will simply turn off the codes associated with it being unplugged but this is not the correct way. The EGR valve needs properly disabling to ensure it is not trying to recirculate exhausts gases whilst still physically working in the engine.

 

 

ADVANTAGES OF EGR
Reduced NOx
Potential reduction of throttling losses on spark ignition engines at part load

 

DISADVANTAGES AND DIFFICULTIES OF EGR
Since EGR reduces the available oxygen in the cylinder, the production of particulates (fuel which has only partially combusted) is increased when EGR is applied. This has traditionally been a problem with diesel engines, where the trade-off between NOx and particulates is a familiar one to calibrators.
The deliberate reduction of the oxygen available in the cylinder will reduce the peak power available from the engine. For this reason the EGR is usually shut off when full power is demanded, so the EGR approach to controlling NOx fails in this situation.
The EGR valve cannot respond instantly to changes in demand, and the exhaust gas takes time to flow around the EGR circuit. This makes the calibration of transient EGR behaviour particularly complex- traditionally the EGR valve has been closed during transients and then re-opened once steady state is achieved. However, the spike in NOx / particulate associated with poor EGR control makes transient EGR behaviour of interest.
The recirculated gas is normally introduced into the intake system before the intakes divide in a multi-cylinder engine. Despite this, perfect mixing of the gas is impossible to achieve at all engine speeds / loads and particularly during transient operation. For example, poor EGR distribution cylinder-to-cylinder may result in one cylinder receiving too much EGR, causing high particulate emissions, while another cylinder receives too little, resulting in high NOx emissions from that cylinder.
Although the term EGR usually refers to deliberate, external EGR, there is also a level of internal EGR. This occurs because the residual combustion gas remaining in the cylinder at the end of the exhaust stroke is mixed with the incoming charge. There is therefore a proportion of internal EGR which must be considered when planning EGR strategies. The scavenging efficiency will vary with engine load, and in an engine fitted with variable valve timing a further parameter must be considered.

 

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