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SCP440 · 5th April 2020, 20:25

EGR has only one purpose, it is to lower the emissions buy increasing the temperature inside the combustion chamber. It will always reduce power but depending on how much exhaust gas is aloud into the chamber will depend on how much effect it has.

An internal combustion engine needs oxygen and fuel, if the combustion chamber is 100% full of this mixture it will produce the maximum amount of power, if you start filling it with other gases like exhaust gas it will produce less power, no in theory but fact.

The problem is modern engines are designed to work with this mixture of exhaust gas, oxygen and fuel so if you remove the exhaust gas without allowing more air in there is little or no advantage.

A good compromise on a lot of engines is to restrict the amount of exhaust gas buy fitting a plate with a hole, depending on your engine will determine the hole size but somewhere between 3 and 6 mm is usually enough.

I also have a Transit van, with the EGR blocked it will run but the engine management light will come on and the engine will go into a partial limp mode, with a 5mm hole it runs great and no engine management light. On my 260 the same is also true, a blanking plate with a 3mm hole is enough to fool the system into thinking it is working as designed but I have a smoother idle, better pickup and a marginal improvement in fuel economy.

5th April 2020, 20:25	#12
SCP440 I really should get out more....... MG ZT-T 260 Join Date: Feb 2016 Location: Witney Posts: 2,504 Thanks: 6 Thanked 910 Times in 571 Posts	EGR has only one purpose, it is to lower the emissions buy increasing the temperature inside the combustion chamber. It will always reduce power but depending on how much exhaust gas is aloud into the chamber will depend on how much effect it has. An internal combustion engine needs oxygen and fuel, if the combustion chamber is 100% full of this mixture it will produce the maximum amount of power, if you start filling it with other gases like exhaust gas it will produce less power, no in theory but fact. The problem is modern engines are designed to work with this mixture of exhaust gas, oxygen and fuel so if you remove the exhaust gas without allowing more air in there is little or no advantage. A good compromise on a lot of engines is to restrict the amount of exhaust gas buy fitting a plate with a hole, depending on your engine will determine the hole size but somewhere between 3 and 6 mm is usually enough. I also have a Transit van, with the EGR blocked it will run but the engine management light will come on and the engine will go into a partial limp mode, with a 5mm hole it runs great and no engine management light. On my 260 the same is also true, a blanking plate with a 3mm hole is enough to fool the system into thinking it is working as designed but I have a smoother idle, better pickup and a marginal improvement in fuel economy. Last edited by SCP440; 5th April 2020 at 20:30..